extrajoints support in motion

New motmod parameter: num_extrajoints

1) An 'extra' joint uses the normal joint homing process but
   transfers control to a new hal pin (joint.N.posthome-cmd)
   after homing.  An independent motion planner/controller
   (limit3 component typically) must be employed to manage
   the 'extra' joint  motion using this input.

2) Includes: simulation configs:
      1extrajoint.ini  XYYZ (4joints) +  1 extra ( 5 joints total)
      2extrajoints.ini XYYZ (4joints) +  2 extra ( 6 joints total)
     12extrajoints.ini XYYZ (4joints) + 12 extra (16 joints total)
   and example M144 command to set extra joints jN.limit3.in

3) motion man page update

Notes:
 1) if num_extrajoints is nonzero, require KINEMATICS_BOTH
    in order to make sensible axis gui displays

 2) by legacy, [KINS]JOINTS=  sets the *total* number of joints
    e.g., num_joints + num_extrajoints
    Example non-motion source files using [KINS]JOINTS:
        a) src/emc/ini/initraj.cc
        b) src/emc/usr_intf/halui.cc
        c) src/emc/usr_intf/axis/scripts/axis.py

------------------------------------------------------------
updates:
rebased to origin/master ae6e7e00a Thu Sep 5 22:27:20 2019 -0700

   1) report numExtraJoints to task
   2) axis.py update joint jog radiobuttons for homing
   3) use #define for ALL_JOINTS,NO_OF_KINS_JOINTS,IS_EXTRAJOINT
   4) axis.py formerly would not 'unhome all' unless machine on
   5) add demo ini for 16 joints (12 extra)
   6) glcanon.py posstrs minor format

------------------------------------------------------------

configs/sim/axis/extrajoints/12extrajoints.ini

@@ -0,0 +1,227 @@
+[EMC]
+MACHINE = 12extrajoints
+VERSION = 1.1
+
+[APPLICATIONS]
+APP = halshow --fformat %.6f extrajoints.halshow
+# joint4 example:
+APP = sim_pin --title "j4 extrajoint" \
+      j4.limit3.min \
+      j4.limit3.max \
+      j4.limit3.maxv \
+      j4.limit3.maxa \
+      j4.limit3.in 
+
+
+[KINS]
+JOINTS = 16
+#NOTE: 4 conventional joints, 12 extra (motmod) total=16
+KINEMATICS = trivkins coordinates=XYYZ kinstype=both
+
+[EMCMOT]
+EMCMOT       = motmod num_extrajoints=12
+SERVO_PERIOD = 1000000
+
+[HAL]
+TWOPASS = on
+HALFILE = LIB:basic_sim.tcl
+HALFILE = ./12extrajoints.tcl
+HALUI   = halui
+
+[DISPLAY]
+DISPLAY = axis
+MAX_LINEAR_VELOCITY = 1
+PROGRAM_PREFIX = .
+
+[TASK]
+TASK = milltask
+CYCLE_TIME = 0.001
+
+[RS274NGC]
+PARAMETER_FILE = sim.var
+
+[EMCIO]
+EMCIO = io
+CYCLE_TIME = 0.100
+
+[TRAJ]
+COORDINATES = XYYZ
+LINEAR_UNITS = inch
+ANGULAR_UNITS = degree
+
+[JOINT_0]
+TYPE = LINEAR
+HOME_SEQUENCE     =   0
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MAX_VELOCITY      =  10
+MAX_ACCELERATION  = 100
+
+[JOINT_1]
+TYPE = LINEAR
+HOME_SEQUENCE     =  -1
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MAX_VELOCITY      =  10
+MAX_ACCELERATION  = 100
+
+[JOINT_2]
+TYPE = LINEAR
+HOME_SEQUENCE     =  -1
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MAX_VELOCITY      =  10
+MAX_ACCELERATION  = 100
+
+[JOINT_3]
+TYPE = LINEAR
+HOME_SEQUENCE     =   2
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MAX_VELOCITY      =  10
+MAX_ACCELERATION  = 100
+
+[JOINT_4]
+# this 'extra' joint is managed by a
+# limit3 component after homing
+TYPE = LINEAR
+HOME_SEQUENCE     =   3
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MIN_LIMIT         = -10
+MAX_LIMIT         =  10
+MAX_VELOCITY      =   5
+MAX_ACCELERATION  = 100
+
+[JOINT_5]
+# this 'extra' joint is managed by a
+# limit3 component after homing
+TYPE = LINEAR
+HOME_SEQUENCE     =   4
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MIN_LIMIT         = -10
+MAX_LIMIT         =  10
+MAX_VELOCITY      =   5
+MAX_ACCELERATION  = 100
+
+[JOINT_6]
+# this 'extra' joint is managed by a
+# limit3 component after homing
+TYPE = LINEAR
+HOME_SEQUENCE     =   5
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MIN_LIMIT         = -10
+MAX_LIMIT         =  10
+MAX_VELOCITY      =   5
+MAX_ACCELERATION  = 100
+
+[JOINT_7]
+# this 'extra' joint is managed by a
+# limit3 component after homing
+TYPE = LINEAR
+HOME_SEQUENCE     =   6
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MIN_LIMIT         = -10
+MAX_LIMIT         =  10
+MAX_VELOCITY      =   5
+MAX_ACCELERATION  = 100
+
+[JOINT_8]
+# this 'extra' joint is managed by a
+# limit3 component after homing
+TYPE = LINEAR
+HOME_SEQUENCE     =   7
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MIN_LIMIT         = -10
+MAX_LIMIT         =  10
+MAX_VELOCITY      =   5
+MAX_ACCELERATION  = 100
+
+[JOINT_9]
+# this 'extra' joint is managed by a
+# limit3 component after homing
+TYPE = LINEAR
+HOME_SEQUENCE     =   8
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MIN_LIMIT         = -10
+MAX_LIMIT         =  10
+MAX_VELOCITY      =   5
+MAX_ACCELERATION  = 100
+
+[JOINT_10]
+# this 'extra' joint is managed by a
+# limit3 component after homing
+TYPE = LINEAR
+HOME_SEQUENCE     =   9
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MIN_LIMIT         = -10
+MAX_LIMIT         =  10
+MAX_VELOCITY      =   5
+MAX_ACCELERATION  = 100
+
+[JOINT_11]
+# this 'extra' joint is managed by a
+# limit3 component after homing
+TYPE = LINEAR
+HOME_SEQUENCE     =  10
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MIN_LIMIT         = -10
+MAX_LIMIT         =  10
+MAX_VELOCITY      =   5
+MAX_ACCELERATION  = 100
+
+[JOINT_12]
+# this 'extra' joint is managed by a
+# limit3 component after homing
+TYPE = LINEAR
+HOME_SEQUENCE     =  11
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MIN_LIMIT         = -10
+MAX_LIMIT         =  10
+MAX_VELOCITY      =   5
+MAX_ACCELERATION  = 100
+
+[JOINT_13]
+# this 'extra' joint is managed by a
+# limit3 component after homing
+TYPE = LINEAR
+HOME_SEQUENCE     =  12 
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MIN_LIMIT         = -10
+MAX_LIMIT         =  10
+MAX_VELOCITY      =   5
+MAX_ACCELERATION  = 100
+
+[JOINT_14]
+# this 'extra' joint is managed by a
+# limit3 component after homing
+TYPE = LINEAR
+HOME_SEQUENCE     =  13 
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MIN_LIMIT         = -10
+MAX_LIMIT         =  10
+MAX_VELOCITY      =   5
+MAX_ACCELERATION  = 100
+
+[JOINT_15]
+# Uses IMMEDIATE homing
+# this 'extra' joint is managed by a
+# limit3 component after homing
+TYPE = LINEAR
+HOME_SEQUENCE     =  14 
+HOME_SEARCH_VEL   =   0
+HOME_LATCH_VEL    =   0
+MIN_LIMIT         = -10
+MAX_LIMIT         =  10
+MAX_VELOCITY      =   5
+MAX_ACCELERATION  = 100

configs/sim/axis/extrajoints/12extrajoints.tcl

@@ -0,0 +1,23 @@
+# 12extrajoints.tcl (requires [HAL]TWOPASS
+
+set min_joint_num  4 ;# first extra joint
+set max_joint_num 15 ;# last  extra joint
+
+for {set j $min_joint_num} {$j <= $max_joint_num} {incr j} {
+  # use limit3 for motion planning:
+  loadrt limit3 names=j${j}.limit3
+  addf j${j}.limit3 servo-thread
+  
+  # These constraints apply to homing managed by
+  # LinuxCNC and post-homing managed by the limit3 component:
+  setp j${j}.limit3.min  [set ::JOINT_[set j](MIN_LIMIT)]
+  setp j${j}.limit3.max  [set ::JOINT_[set j](MAX_LIMIT)]
+  setp j${j}.limit3.maxv [set ::JOINT_[set j](MAX_VELOCITY)]
+  setp j${j}.limit3.maxa [set ::JOINT_[set j](MAX_ACCELERATION)]
+
+  net  J${j}:out    <= j${j}.limit3.out
+  net  J${j}:out    => joint.${j}.posthome-cmd
+
+  net  J${j}.enable <= joint.${j}.homed
+  net  J${j}.enable => j${j}.limit3.enable
+}

configs/sim/axis/extrajoints/1extrajoint.hal

@@ -0,0 +1,61 @@
+# 1extrajoint demo
+# immediate homing -- jog joint4 to make a motor-offset before homing
+loadrt [KINS]KINEMATICS
+loadrt [EMCMOT]EMCMOT servo_period_nsec=[EMCMOT]SERVO_PERIOD num_joints=[KINS]JOINTS
+
+addf motion-command-handler servo-thread
+addf motion-controller servo-thread
+
+net estop-loop iocontrol.0.user-enable-out iocontrol.0.emc-enable-in
+
+net J0:loop <= joint.0.motor-pos-cmd
+net J0:loop => joint.0.motor-pos-fb
+
+net J1:loop <= joint.1.motor-pos-cmd
+net J1:loop => joint.1.motor-pos-fb
+
+net J2:loop <= joint.2.motor-pos-cmd
+net J2:loop => joint.2.motor-pos-fb
+
+net J3:loop <= joint.3.motor-pos-cmd
+net J3:loop => joint.3.motor-pos-fb
+#--------------------------------------------
+# extra joint (joint4)
+
+# For simulation just connect pos-cmd to pos-fb:
+net J4:loop <= joint.4.motor-pos-cmd
+net J4:loop => joint.4.motor-pos-fb
+
+# NOTE: For a stepgen in position control mode:
+#       net J4:loop <= joint.4.motor-pos-cmd
+#       net J4:loop => joint.4.motor-pos-fb
+#       net J4:loop => stepgen_position_command
+
+# NOTE: A stepgen can be also used in velocity control mode
+#       with a PID loop but it is not necessarily required
+#       and position mode control is much simpler
+
+# NOTE: For a pid motor controller (motor/amplifier/encoder):
+#       net J4:cmd <= joint.4.motor-pos-cmd
+#       net J4:cmd => pid_command_input
+#       net J4:fb  <= encoder_measurement_output
+#       net J4:fb  => joint.4.motor-pos-fb
+
+#-----------------------------------------------------------
+# motion planner for extra joint (joint4)
+loadrt limit3 names=j4.limit3
+
+# These constraints apply to homing managed by
+# LinuxCNC and post-homing managed by the limit3 component:
+setp j4.limit3.min    [JOINT_4]MIN_LIMIT
+setp j4.limit3.max    [JOINT_4]MAX_LIMIT
+setp j4.limit3.maxv   [JOINT_4]MAX_VELOCITY
+setp j4.limit3.maxa   [JOINT_4]MAX_ACCELERATION
+
+addf j4.limit3 servo-thread
+
+net  J4:out <= j4.limit3.out
+net  J4:out => joint.4.posthome-cmd
+
+net  J4:enable <= joint.4.homed
+net  J4:enable => j4.limit3.enable

configs/sim/axis/extrajoints/1extrajoint.ini

@@ -0,0 +1,86 @@
+# This sim config uses 'immediate' homing
+# To demonstrate motor-offsets:
+#   jog the extra joint(4) away from its turn-on position
+#   then home-all
+
+[EMC]
+MACHINE = 1extrajoint
+VERSION = 1.1
+
+[APPLICATIONS]
+APP = halshow --fformat %.6f extrajoints.halshow
+APP = sim_pin --title "j4 extrajoint" \
+      j4.limit3.min \
+      j4.limit3.max \
+      j4.limit3.maxv \
+      j4.limit3.maxa \
+      j4.limit3.in
+
+[KINS]
+JOINTS = 5
+# NOTE: 4 kinematic joints + 1 extra (motmod) total=5
+KINEMATICS = trivkins coordinates=XYYZ kinstype=both
+
+[EMCMOT]
+EMCMOT       = motmod num_extrajoints=1
+SERVO_PERIOD = 1000000
+
+[HAL]
+HALFILE = 1extrajoint.hal
+HALUI   = halui
+
+
+[DISPLAY]
+DISPLAY = axis
+MAX_LINEAR_VELOCITY = 1
+PROGRAM_PREFIX = .
+
+[TASK]
+TASK = milltask
+CYCLE_TIME = 0.001
+
+[RS274NGC]
+PARAMETER_FILE = sim.var
+
+[EMCIO]
+EMCIO = io
+CYCLE_TIME = 0.100
+
+[TRAJ]
+COORDINATES = XYYZ
+LINEAR_UNITS = inch
+ANGULAR_UNITS = degree
+
+[JOINT_0]
+TYPE = LINEAR
+HOME_SEQUENCE     =   1
+MAX_VELOCITY      =  10
+MAX_ACCELERATION  = 100
+
+[JOINT_1]
+TYPE = LINEAR
+HOME_SEQUENCE     =  -2
+MAX_VELOCITY      =  10
+MAX_ACCELERATION  = 100
+
+[JOINT_2]
+TYPE = LINEAR
+HOME_SEQUENCE     =  -2
+MAX_VELOCITY      =  10
+MAX_ACCELERATION  = 100
+
+[JOINT_3]
+TYPE = LINEAR
+HOME_SEQUENCE     =   3
+MAX_VELOCITY      =  10
+MAX_ACCELERATION  = 100
+
+[JOINT_4]
+# this 'extra' joint is managed by a
+# limit3 component after homing
+TYPE = LINEAR
+HOME_SEQUENCE     =   0
+MIN_LIMIT         = -10
+MAX_LIMIT         =  10
+MAX_VELOCITY      =   5
+MAX_ACCELERATION  = 100

configs/sim/axis/extrajoints/1extrajoint.txt

@@ -0,0 +1,37 @@
+1extrajoint demo
+
+Demo of the motmod num_extrajoints= parameter
+
+a) XYYZ correspond one-to-one to
+   joints 0123
+b) Joint4 is an 'extra joint' that is
+   not related to any axis letter but
+   is managed independently by a limit3
+   component.
+c) All joints use 'immediate homing'
+d) Using extra joints requires
+   NON-identity kinematics and all
+   joints (including joint4) must be
+   homed before switching to world
+   mode.
+e) A halshow app is opened to display
+   key pin values
+f) A sim_pin app is opened to set key
+   pin values
+
+Usage:
+1) F1        (Estop Off)
+2) F2        (Machine On)
+3) jog joint4 to create a small offset
+4) Ctrl-HOME (Home all)
+5) demonstrate joint.4 movement using
+   the provided M144 mdi command:
+   M144 P4 Q1.23 ;move joint.4 to 1.23
+   M144 P4 Q3.21 ;move joint.4 to 3.21
+6) Alternately, demonstrate joint.[45]
+   movement using sim_pin settings:
+     j4.limit3.min  min value
+     j4.limit3.max  max value
+     j4.limit3.maxv max velocity
+     j4.limit3.maxa max acceleration
+     j4.limit3.in   requested value

configs/sim/axis/extrajoints/2extrajoints.hal

@@ -0,0 +1,30 @@
+# use limit3 for motion planning:
+loadrt limit3 names=j4.limit3,j5.limit3
+
+# These constraints apply to homing managed by
+# LinuxCNC and post-homing managed by the limit3 component:
+setp j4.limit3.min    [JOINT_4]MIN_LIMIT
+setp j4.limit3.max    [JOINT_4]MAX_LIMIT
+setp j4.limit3.maxv   [JOINT_4]MAX_VELOCITY
+setp j4.limit3.maxa   [JOINT_4]MAX_ACCELERATION
+
+addf j4.limit3 servo-thread
+
+net  J4:out <= j4.limit3.out
+net  J4:out => joint.4.posthome-cmd
+
+net  J4.enable <= joint.4.homed
+net  J4.enable => j4.limit3.enable
+
+setp j5.limit3.min    [JOINT_5]MIN_LIMIT
+setp j5.limit3.max    [JOINT_5]MAX_LIMIT
+setp j5.limit3.maxv   [JOINT_5]MAX_VELOCITY
+setp j5.limit3.maxa   [JOINT_5]MAX_ACCELERATION
+
+addf j5.limit3 servo-thread
+
+net  J5:out <= j5.limit3.out
+net  J5:out => joint.5.posthome-cmd
+
+net  J5.enable <= joint.5.homed
+net  J5.enable => j5.limit3.enable

configs/sim/axis/extrajoints/2extrajoints.ini

@@ -0,0 +1,111 @@
+[EMC]
+MACHINE      = 2extrajoints
+VERSION = 1.1
+
+[APPLICATIONS]
+APP = halshow --fformat %.6f extrajoints.halshow
+APP = sim_pin --title "j4 extrajoint" \
+      j4.limit3.min \
+      j4.limit3.max \
+      j4.limit3.maxv \
+      j4.limit3.maxa \
+      j4.limit3.in 
+
+APP = sim_pin --title "j5 extrajoints" \
+      j5.limit3.min \
+      j5.limit3.max \
+      j5.limit3.maxv \
+      j5.limit3.maxa \
+      j5.limit3.in
+
+
+[KINS]
+JOINTS = 6
+#NOTE: 4 conventional joints, 2 extra (motmod) total=6
+KINEMATICS = trivkins coordinates=XYYZ kinstype=both
+
+[EMCMOT]
+EMCMOT       = motmod num_extrajoints=2
+SERVO_PERIOD = 1000000
+
+[HAL]
+HALFILE = LIB:basic_sim.tcl
+HALFILE = ./2extrajoints.hal
+HALUI   = halui
+
+[DISPLAY]
+DISPLAY = axis
+MAX_LINEAR_VELOCITY = 1
+PROGRAM_PREFIX = .
+
+[TASK]
+TASK = milltask
+CYCLE_TIME = 0.001
+
+[RS274NGC]
+PARAMETER_FILE = sim.var
+
+[EMCIO]
+EMCIO = io
+CYCLE_TIME = 0.100
+
+[TRAJ]
+COORDINATES = XYYZ
+LINEAR_UNITS = inch
+ANGULAR_UNITS = degree
+
+[JOINT_0]
+TYPE = LINEAR
+HOME_SEQUENCE     =   1
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MAX_VELOCITY      =  10
+MAX_ACCELERATION  = 100
+
+[JOINT_1]
+TYPE = LINEAR
+HOME_SEQUENCE     =  -2
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MAX_VELOCITY      =  10
+MAX_ACCELERATION  = 100
+
+[JOINT_2]
+TYPE = LINEAR
+HOME_SEQUENCE     =  -2
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MAX_VELOCITY      =  10
+MAX_ACCELERATION  = 100
+
+[JOINT_3]
+TYPE = LINEAR
+HOME_SEQUENCE     =   3
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MAX_VELOCITY      =  10
+MAX_ACCELERATION  = 100
+
+[JOINT_4]
+# this 'extra' joint is managed by a
+# limit3 component after homing
+TYPE = LINEAR
+HOME_SEQUENCE     =   0
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MIN_LIMIT         = -10
+MAX_LIMIT         =  10
+MAX_VELOCITY      =   5
+MAX_ACCELERATION  = 100
+
+[JOINT_5]
+# this 'extra' joint is managed by a
+# limit3 component after homing
+TYPE = LINEAR
+HOME_SEQUENCE     =   0
+HOME_SEARCH_VEL   =  20
+HOME_LATCH_VEL    =  20
+MIN_LIMIT         = -10
+MAX_LIMIT         =  10
+MAX_VELOCITY      =   5
+MAX_ACCELERATION  = 100

configs/sim/axis/extrajoints/2extrajoints.txt

@@ -0,0 +1,46 @@
+2extrajoints demo
+
+Demo of the motmod num_extrajoints= parameter
+
+a) XYYZ correspond one-to-one to
+   joints 0123
+b) joint.4 and joint.5 are 'extra'
+   joints not related to any axis
+   letter but managed independently by
+   limit3 components.
+c) The configuration uses basic_sim.tcl
+   and simulates home switches for all
+   joints.
+d) Using extra joints requires
+   NON-identity kinematics and all
+   joints (including joint4) must be
+   homed before switching to world
+   mode.
+e) A halshow app is opened to display
+   key pin values
+f) A sim_pin app is opened to set key
+   pin values
+
+Usage:
+1) F1        (Estop Off)
+2) F2        (Machine On)
+3) optionally jog joint.4 and joint.5
+   prior to homing to observe motor
+   offset
+4) Ctrl-HOME (Home all)
+5) demonstrate joint.[45] movement
+   using the provided M144 mdi
+   command:
+   M144 P4 Q1.23 move joint.4 to 1.23
+   M144 P4 Q4.56 move joint.4 to 4.56
+   M144 P5 Q3.21 move joint.5 to 3.21
+   M144 P5 Q2.22 move joint.5 to 2.22
+   etc.
+6) Alternately, demonstrate joint.[45]
+   movement using sim_pin settings:
+     j4.limit3.min  min value
+     j4.limit3.max  max value
+     j4.limit3.maxv max velocity
+     j4.limit3.maxa max acceleration
+     j4.limit3.in   requested value
+     similar for j5

configs/sim/axis/extrajoints/M144

@@ -0,0 +1,35 @@
+#!/usr/bin/tclsh
+
+# M144 demo for extra joints 
+# Usage: M144 [Pjoint_num] [Qposition]
+
+# Mcodes substitute "-1.000000" for omitted p,q values
+# so these are handled as special cases
+# Note: this also disallows a q value of -1 (sigh)
+
+set min_joint_num  4
+set max_joint_num 15
+
+proc fail {msg} {
+  puts "\nFAIL:  $::argv0 $msg"
+  puts "Usage: $::argv0 P<jointnumber> Q<position>"
+  exit 1
+}
+
+set p [lindex $::argv 0]
+set q [lindex $::argv 1]
+
+if {"$p" == "-1.000000"} {fail "Missing Pvalue"}
+if {"$q" == "-1.000000"} {fail "Missing Qvalue (or -1)"}
+
+set p [expr int($p)]
+if {$p < $min_joint_num || $p > $max_joint_num} {
+  fail "Bad Pvalue (extra joint number) <$p>"
+}
+
+set cmd "halcmd setp j${p}.limit3.in $q"
+if [catch {eval exec $cmd} msg] {
+  fail "Command:$cmd\n$msg"
+}
+puts "\nOK: $::argv0: $cmd"
+exit 0

configs/sim/axis/extrajoints/README

@@ -0,0 +1,18 @@
+extrajoints demos
+
+1extrajoint
+   5 joints total
+   1 extra joint (joint.4)
+   immediate homing
+   (jog joint4 before homing to
+   create a small motor offset)
+
+2extrajoints
+   6 joints total
+   2 extra joints (joint.4,5)
+   simulated home switches
+
+12extrajoints
+   16 joints total
+   12 extra joints (joint.4-15)
+   simulated home switches

configs/sim/axis/extrajoints/extrajoints.halshow

@@ -0,0 +1,28 @@
+pin+j4.limit3.in
+pin+j4.limit3.out
+
+pin+joint.4.posthome-cmd
+pin+joint.4.homed
+pin+joint.4.motor-pos-cmd
+pin+joint.4.motor-pos-fb
+pin+joint.4.motor-offset
+
+pin+j4.limit3.max
+pin+j4.limit3.min
+pin+j4.limit3.maxv
+pin+j4.limit3.maxa
+
+pin+j5.limit3.in
+pin+j5.limit3.out
+
+pin+joint.5.posthome-cmd
+pin+joint.5.homed
+pin+joint.5.motor-pos-cmd
+pin+joint.5.motor-pos-fb
+pin+joint.5.motor-offset
+
+pin+j5.limit3.max
+pin+j5.limit3.min
+pin+j5.limit3.maxv
+pin+j5.limit3.maxa
+

docs/man/man9/motion.9

@@ -8,17 +8,23 @@
 .SH NAME
 motion \- accepts NML motion commands, interacts with HAL in realtime
 .SH SYNOPSIS
-\fBloadrt motmod [base_period_nsec=\fIperiod\fB] [base_thread_fp=\fI0 or 1\fB] [servo_period_nsec=\fIperiod\fB] [traj_period_nsec=\fIperiod\fB] [num_joints=\fI[1-16]\fB] [num_dio=\fI[1-64]\fB] [num_aio=\fI[1-64]\fB] [num_spindles=\fI[1-8]\fB]\fR  \fB[unlock_joints_mask=\fR\fIjointmask\fR\fB]\fR
+\fBloadrt motmod [base_period_nsec=\fIperiod\fB] [base_thread_fp=\fI0 or 1\fB] [servo_period_nsec=\fIperiod\fB] [traj_period_nsec=\fIperiod\fB] [num_joints=\fI[1-16]\fB] [num_dio=\fI[1-64]\fB] [num_aio=\fI[1-64]\fB] [num_spindles=\fI[1-8]\fB]\fR  \fB[unlock_joints_mask=\fR\fIjointmask\fR\fB]\fR \fB[num_extrajoints=\fI[0-16]\fB]\fR
 
 The limits for the following items are compile-time settings:
 .TQ
-Number of joints available (num_joints) is set by EMCMOT_MAX_JOINTS.
+\fBnum_joints\fR: Maximum number of joints is set by EMCMOT_MAX_JOINTS.
 .TQ
-Maximum number of digital inputs (num_dio) is set by EMCMOT_MAX_DIO.
+\fBnum_dio\fR: Maximum number of digital inputs is set by EMCMOT_MAX_DIO.
 .TQ
-Maximum number of analog inputs (num_aio) is set by EMCMOT_MAX_AIO.
+\fBnum_aio\fR: Maximum number of analog inputs is set by EMCMOT_MAX_AIO.
 .TQ
-Maximum number of spindles (num_spindles) is set by EMCMOT_MAX_SPINDLES
+\fBnum_spindles\fR: Maximum number of spindles is set by EMCMOT_MAX_SPINDLES
+
+.P
+Optionally the number of Digital I/O is set with num_dio. The number of Analog I/O is set with num_aio. The default is 4 each.
+
+.P
+Pin names starting with "\fBjoint\fR"  or "\fBaxis\fR" are are read and updated by the motion-controller function.
 
 .SH DESCRIPTION
 By default, the base thread does not support floating point.  Software stepping, software encoder counting, and software pwm do not use floating point.  \fBbase_thread_fp\fR can be used to enable floating point in the base thread (for example for brushless DC motor control).
@@ -27,10 +33,29 @@ By default, the base thread does not support floating point.  Software stepping,
 These pins and parameters are created by the realtime \fBmotmod\fR module. This module provides a HAL interface for LinuxCNC's motion planner. Basically \fBmotmod\fR takes in a list of waypoints and generates a nice blended and constraint-limited stream of joint positions to be fed to the motor drives.
 
 .P
-Optionally the number of Digital I/O is set with num_dio. The number of Analog I/O is set with num_aio. The default is 4 each.
+The optional \fBnum_extrajoints\fR parameter specifies a quantity of joints
+that participate in homing but are not used by kinematics transformations.
+After homing, control of an 'extra' joint is transferred to a posthome command
+hal pin (joint.N.posthome-cmd) and the motor feedback value is ignored.  'Extra'
+joints must be managed by independent motion planners/controllers (typically
+using limit3 hal components).  Extra joints maybe unhomed only when motion is
+disabled.
 
-.P
+The maximum \fBnum_extrajoints\fR value is equal to the \fBnum_joints\fR value.
-Pin names starting with "\fBjoint\fR"  or "\fBaxis\fR" are are read and updated by the motion-controller function.
+(Note that using the maximum value would allow no operation in world
+coordinates).  The \fBnum_joints\fR value must be equal to the sum of the
+number of joints used for kinematics calculations plus the number of 'extra'
+joints.
+
+The \fBnum_joints\fR parameter is conventionally set using the ini file
+setting \fB[KINS]JOINTS=\fRvalue.  The \fBnum_extrajoints\fR is set by
+the additional motmod parameter \fB[EMCMOT]motmod num_extrajoints=\fRvalue.
+Hal pin numbering for all joints is zero based [\fB0 ... num_joints-1\fR].
+When specified, 'extra' joints are assigned the last \fBnum_extrajoints\fR
+in the numbering sequence.  For example, specifying [KINS]JOINTS=5 and
+[EMCMOT]motmod num_extrajoints=2 for a 3 joint trivkins configuration
+\fB[KINS] KINEMATICS=trivkins coordinates=xyz\fR uses joints 0,1,2 for
+the kinematic joints and joints 3,4 for the 'extra' joints.
 
 .SH  MOTION PINS
 
@@ -431,7 +456,13 @@ The joint's commanded velocity
 .TP
 \fBjoint.\fIN\fB.wheel\-jog\-active\fR OUT BIT \fB(DEBUG)\fR
 
-.SH JOINT UNLOCK PINS
+.SH JOINT posthome pins
+Each joint designated as an 'extra' joint is provided with a hal pin
+\fBjoint.N.posthome-cmd\fR.  The pin value is ignored prior to homing.
+After homing, the pin value is augmented by the motor offset value
+and routed to the \fBjoint.N.motor-pos-cmd\fR.
+
+.SH JOINT unlock pins
 The joint pins used for unlocking a joint
 (\fBjoint.N.unlock\fR, \fBjoint.N.is-unlocked\fR),
 are created according to the \fBunlock_joints_mask=\fRjointmask parameter for motmod.  These pins may be required for locking indexers (typically a rotary joint)

docs/src/getting-started/updating-linuxcnc.txt

@@ -1209,6 +1209,15 @@ motion modules, the python interface, the axis gui, and the test suite.
 The maximum number of joints (EMCMOT_MAX_JOINTS) increased from 9
 to 16.  The axis gui now supports display of up to 16 joints.
 
+==== Extra Joints
+
+A new motmod parameter (num_extrajoints) specifies joints that are
+homed by conventional joint homing methods but controlled by new hal
+pins (joint.N.posthome-cmd) after homing.  Such joints may be
+managed by independent motion planner/controllers in hal and manipulated
+from gcode using custom M-codes.  See the motion man page for
+more info.
+
 ==== Homing
 
 A homing api is provided by src/emc/motion/homing.h to support users'

lib/hallib/check_config.tcl

@@ -136,6 +136,25 @@ proc validate_identity_kins_limits {} {
   }
   return $emsg
 } ;# validate_identity_kins_limits
+
+proc check_extrajoints {} {
+  if ![info exists ::EMCMOT(EMCMOT)] return
+  if {[string first motmod $::EMCMOT(EMCMOT)] <= 0} return
+  set mot [split [lindex $::EMCMOT(EMCMOT) 0]]
+  foreach item $mot {
+    set pair [split $item =]
+    set parm [lindex $pair 0]
+    set val  [lindex $pair 1]
+    if {"$parm" == "num_extrajoints"} {
+      set ::num_extrajoints $val
+    }
+  }
+  if [info exists ::num_extrajoints] {
+     lappend ::wmsg [format "Extra joints specified=%d\n \
+\[KINS\]JOINTS=%d must accomodate kinematic joints *plus* extra joints " \
+                     $::num_extrajoints $::KINS(JOINTS)]
+  }
+} ;#check_extrajoints
 #----------------------------------------------------------------------
 # begin
 package require Linuxcnc ;# parse_ini
@@ -182,6 +201,7 @@ switch $::kins(module) {
     exit 0
   }
 }
+check_extrajoints
 
 
 #parray ::kins

lib/hallib/sim_lib.tcl

@@ -59,16 +59,30 @@ proc check_ini_items {} {
      }
   }
 
+  set n_extrajoints 0
+  if [info exists ::EMCMOT(EMCMOT)] {
+    set mot [split [lindex $::EMCMOT(EMCMOT) 0]]
+    if {[string first motmod $mot] >= 0} {
+      foreach item $mot {
+        if {[string first num_extrajoints= $item] < 0} continue
+          set n_extrajoints [lindex [split $item =] end]
+      } ;# foreach
+    }
+  }
+
   set kins [split [lindex $::KINS(KINEMATICS) 0]]
   if {[string first trivkins $kins] >= 0} {
     foreach item $kins {
       if {[string first coordinates= $item] < 0} continue
       set     tcoords [lindex [split $item =] end]
       set len_tcoords [string len $tcoords]
-        if {$len_tcoords != $::KINS(JOINTS)} {
+      set expected_joints [expr $len_tcoords + $n_extrajoints]
+      if {$expected_joints != $::KINS(JOINTS)} {
           set m "\ncheck_ini_items: WARNING:\n"
           set m "$m  trivkins coordinates=$tcoords specifies $len_tcoords joints\n"
-          set m "$m  but \[KINS\]JOINTS is $::KINS(JOINTS)\n"
+          set m "$m  trivkins extrajoints=$n_extrajoints\n"
+          set m "$m  trivkins totaljoints=$expected_joints\n"
+          set m "$m  !!! but \[KINS\]JOINTS=$::KINS(JOINTS)\n"
           puts stderr $m
       }
     } ;# foreach
@@ -88,9 +102,7 @@ proc setup_kins {axes} {
 
   puts stderr "setup_kins: cmd=$cmd"
   if [catch {eval $cmd} msg] {
-    puts stderr "msg=$msg"
+    puts stderr "\nmsg=$msg\n"
-    # if fail, try without coordinates parameters
-    $cmd
   }
 
   # set up axis indices for known kins
@@ -115,13 +127,21 @@ proc core_sim {axes
   setup_kins $axes
 
   if {"$emcmot" == "motmod"} {
-    loadrt $emcmot \
+    if [catch {loadrt $emcmot \
                       base_period_nsec=$base_period \
                       servo_period_nsec=$servo_period \
-      num_joints=$number_of_joints
+                      num_joints=$number_of_joints} msg
+       ] {
+       # typ: too many joints attempted
+       puts stderr "\n"
+       puts stderr "core_sim: loadrt $emcmot FAIL"
+       puts stderr "     msg=$msg\n"
+       exit 1
+    }
   } else {
      # known special case with additional parameter:
      #       unlock_joint_mask=0xNN
+     #       num_extrajoints=n
      set module  [split [lindex $emcmot 0]]
      set modname [lindex $module 0]
      set modparm [lreplace $module 0 0]
@@ -213,7 +233,7 @@ proc make_ddts {number_of_joints} {
     incr ddt_ct 2
     if {$ddt_ct > $ddt_limit} {
       puts stderr "make_ddts: number of ddts limited to $ddt_limit"
-      continue
+      break
     }
     set ddt_names "${ddt_names},J${jno}_vel,J${jno}_accel"
   }

lib/python/rs274/glcanon.py

@@ -1532,7 +1532,7 @@ class GlCanonDraw:
         else:
             # N.B. no conversion here because joint positions are unitless
             #      joint_mode and display_joint
-            posstrs = ["  %s:% 9.4f" % i for i in
+            posstrs = [" %2s:% 9.4f" % i for i in
                 zip(range(self.get_num_joints()), s.joint_actual_position)]
             droposstrs = posstrs
         return limit, homed, posstrs, droposstrs

src/emc/motion/command.c

@@ -83,7 +83,7 @@ bool checkAllHomed(void)
     int joint_num;
     emcmot_joint_t *joint;
 
-    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+    for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 	joint = &joints[joint_num];
 	if (!GET_JOINT_ACTIVE_FLAG(joint)) {
 	    /* if joint is not active, don't even look at its limits */
@@ -105,7 +105,7 @@ STATIC int limits_ok(void)
     int joint_num;
     emcmot_joint_t *joint;
 
-    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+    for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 	/* point to joint data */
 	joint = &joints[joint_num];
 	if (!GET_JOINT_ACTIVE_FLAG(joint)) {
@@ -141,7 +141,7 @@ STATIC int joint_jog_ok(int joint_num, double vel)
 	   we skip the following tests... */
 	return 1;
     }
-    if (joint_num < 0 || joint_num >= emcmotConfig->numJoints) {
+    if (joint_num < 0 || joint_num >= ALL_JOINTS) {
 	reportError(_("Can't jog invalid joint number %d."), joint_num);
 	return 0;
     }
@@ -252,7 +252,7 @@ STATIC int inRange(EmcPose pos, int id, char *move_type)
     /* Now, check that the endpoint puts the joints within their limits too */
 
     /* fill in all joints with 0 */
-    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+    for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 	joint_pos[joint_num] = 0.0;
     }
 
@@ -264,7 +264,7 @@ STATIC int inRange(EmcPose pos, int id, char *move_type)
 	return 0;
     }
 
-    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+    for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 	/* point to joint data */
 	joint = &joints[joint_num];
 
@@ -310,7 +310,7 @@ void clearHomes(int joint_num)
     int n;
     if (emcmotConfig->kinType == KINEMATICS_INVERSE_ONLY) {
 	if (rehomeAll) {
-	    for (n = 0; n < emcmotConfig->numJoints; n++) {
+	    for (n = 0; n < ALL_JOINTS; n++) {
                 set_joint_homed(joint_num,0);
 	    }
 	} else {
@@ -462,11 +462,11 @@ void emcmotCommandHandler(void *arg, long period)
                abort = 1;
            }
            if (   !GET_MOTION_TELEOP_FLAG()
-               && (joint_num >= emcmotConfig->numJoints || joint_num <  0)
+               && (joint_num >= ALL_JOINTS || joint_num <  0)
               ) {
                rtapi_print_msg(RTAPI_MSG_ERR,
                     "Joint jog requested for undefined joint number=%d (min=0,max=%d)",
-                    joint_num,emcmotConfig->numJoints-1);
+                    joint_num,ALL_JOINTS-1);
                return;
            }
            if (GET_MOTION_TELEOP_FLAG()) {
@@ -495,7 +495,7 @@ void emcmotCommandHandler(void *arg, long period)
           return;
         }
 
-        if (joint_num >= 0 && joint_num < emcmotConfig->numJoints) {
+        if (joint_num >= 0 && joint_num < ALL_JOINTS) {
             joint = &joints[joint_num];
             if (   (   emcmotCommand->command == EMCMOT_JOG_CONT
                     || emcmotCommand->command == EMCMOT_JOG_INCR
@@ -544,7 +544,7 @@ void emcmotCommandHandler(void *arg, long period)
 	    } else if (GET_MOTION_COORD_FLAG()) {
 		tpAbort(&emcmotDebug->coord_tp);
 	    } else {
-		for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+		for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 		    /* point to joint struct */
 		    joint = &joints[joint_num];
 		    /* tell joint planner to stop */
@@ -557,7 +557,7 @@ void emcmotCommandHandler(void *arg, long period)
 	    }
             SET_MOTION_ERROR_FLAG(0);
 	    /* clear joint errors (regardless of mode) */
-	    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+	    for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 		/* point to joint struct */
 		joint = &joints[joint_num];
 		/* update status flags */
@@ -637,14 +637,17 @@ void emcmotCommandHandler(void *arg, long period)
 
 	case EMCMOT_SET_NUM_JOINTS:
 	    /* set the global NUM_JOINTS, which must be between 1 and
-	       EMCMOT_MAX_JOINTS, inclusive */
+	       EMCMOT_MAX_JOINTS, inclusive.
+	       Called  by task using [KINS]JOINTS= which is typically
+	       the same value as the motmod num_joints= parameter
+	    */
 	    rtapi_print_msg(RTAPI_MSG_DBG, "SET_NUM_JOINTS");
 	    rtapi_print_msg(RTAPI_MSG_DBG, " %d", emcmotCommand->joint);
 	    if (( emcmotCommand->joint <= 0 ) ||
 		( emcmotCommand->joint > EMCMOT_MAX_JOINTS )) {
 		break;
 	    }
-	    emcmotConfig->numJoints = emcmotCommand->joint;
+	    ALL_JOINTS = emcmotCommand->joint;
 	    break;
 
 	case EMCMOT_SET_NUM_SPINDLES:
@@ -724,7 +727,7 @@ void emcmotCommandHandler(void *arg, long period)
 	    } else {
 		rtapi_print_msg(RTAPI_MSG_DBG, "override on");
 		emcmotStatus->overrideLimitMask = 0;
-		for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+		for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 		    /* point at joint data */
 		    joint = &joints[joint_num];
 		    /* only override limits that are currently tripped */
@@ -737,7 +740,7 @@ void emcmotCommandHandler(void *arg, long period)
 		}
 	    }
 	    emcmotDebug->overriding = 0;
-	    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+	    for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 		/* point at joint data */
 		joint = &joints[joint_num];
 		/* clear joint errors */
@@ -895,7 +898,7 @@ void emcmotCommandHandler(void *arg, long period)
 	        axis->teleop_tp.max_vel = fabs(emcmotCommand->vel);
 	        axis->teleop_tp.max_acc = axis->acc_limit;
 	        axis->kb_ajog_active = 1;
-                for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+                for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
                     joint = &joints[joint_num];
                     if (joint != 0) { joint->free_tp.enable = 0; }
                 }
@@ -995,7 +998,7 @@ void emcmotCommandHandler(void *arg, long period)
 	        axis->teleop_tp.max_acc = axis->acc_limit;
 	        axis->kb_ajog_active = 1;
 	        axis->teleop_tp.enable = 1;
-                for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+                for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
                     joint = &joints[joint_num];
                     if (joint != 0) { joint->free_tp.enable = 0; }
                 }
@@ -1074,7 +1077,7 @@ void emcmotCommandHandler(void *arg, long period)
                 axis->teleop_tp.max_acc = axis->acc_limit;
                 axis->kb_ajog_active = 1;
                 axis->teleop_tp.enable = 1;
-                for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+                for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
                    joint = &joints[joint_num];
                    if (joint != 0) { joint->free_tp.enable = 0; }
                 }
@@ -1499,7 +1502,7 @@ void emcmotCommandHandler(void *arg, long period)
             if (get_home_sequence(joint_num) < 0) {
                int jj;
                set_home_sequence_state(HOME_SEQUENCE_DO_ONE_SEQUENCE);
-               for (jj = 0; jj < emcmotConfig->numJoints; jj++) {
+               for (jj = 0; jj < ALL_JOINTS; jj++) {
                   if (ABS(get_home_sequence(jj)) == ABS(get_home_sequence(joint_num))) {
                       // set home_state for all joints at same neg sequence
                       set_home_start(jj);
@@ -1527,7 +1530,7 @@ void emcmotCommandHandler(void *arg, long period)
                 /* we want all or none, so these checks need to all be done first.
                  * but, let's only report the first error.  There might be several,
                  * for instance if a homing sequence is running. */
-                for (n = 0; n < emcmotConfig->numJoints; n++) {
+                for (n = 0; n < ALL_JOINTS; n++) {
                     joint = &joints[n];
                     if(GET_JOINT_ACTIVE_FLAG(joint)) {
                         if (get_homing(n)) {
@@ -1539,19 +1542,25 @@ void emcmotCommandHandler(void *arg, long period)
                             return;
                         }
                     }
+                    if (   (n >= NO_OF_KINS_JOINTS)
+                        && (emcmotStatus->motion_state != EMCMOT_MOTION_DISABLED)) {
+                        reportError(_("Cannot unhome extrajoint <%d> with motion enabled"), n);
+                        return;
+                    }
                 }
                 /* we made it through the checks, so unhome them all */
-                for (n = 0; n < emcmotConfig->numJoints; n++) {
+                for (n = 0; n < ALL_JOINTS; n++) {
                     joint = &joints[n];
                     if(GET_JOINT_ACTIVE_FLAG(joint)) {
-/* legacy notes:
+                        /* legacy notes:
-4aa4791cd1 (Chris Radek 2008-02-27 21:07:02 +0000 1310)
+                        4aa4791cd1 (Chris Radek 2008-02-27 21:07:02 +0000 1310)
-
+                        Unhome support, partly based on a patch by Bryant.
-Unhome support, partly based on a patch by Bryant.  Allow unhoming one joint or
+                        Allow unhoming one joint or all (-1) via nml message.
-all (-1) via nml message.  A special unhome mode (-2) unhomes only the joints
+                        A special unhome mode (-2) unhomes only the joints
-marked as VOLATILE_HOME in the ini.  task could use this to unhome some joints,
+                        marked as VOLATILE_HOME in the ini.  task could use this
-based on policy, at various state changes.  This part is unimplemented so far.
+                        to unhome some joints, based on policy, at various state changes.
-*/
+                        This part is unimplemented so far.
+                        */
                         /* if -2, only unhome the volatile_home joints */
                         if( (joint_num != -2) || get_home_is_volatile(n) ) {
                             set_joint_homed(n, 0);
@@ -1559,8 +1568,13 @@ based on policy, at various state changes.  This part is unimplemented so far.
 
                     }
                 }
-            } else if (joint_num < emcmotConfig->numJoints) {
+            } else if (joint_num < ALL_JOINTS) {
                 /* request was for only one joint */
+                if (   (joint_num >= NO_OF_KINS_JOINTS)
+                    && (emcmotStatus->motion_state != EMCMOT_MOTION_DISABLED)) {
+                    reportError(_("Cannot unhome extrajoint <%d> with motion enabled"), joint_num);
+                    return;
+                }
                 if(GET_JOINT_ACTIVE_FLAG(joint)) {
                     if (get_homing(joint_num) ) {
                         reportError(_("Cannot unhome while homing, joint %d"), joint_num);
@@ -1576,7 +1590,7 @@ based on policy, at various state changes.  This part is unimplemented so far.
                 }
             } else {
                 /* invalid joint number specified */
-                reportError(_("Cannot unhome invalid joint %d (max %d)"), joint_num, (emcmotConfig->numJoints-1));
+                reportError(_("Cannot unhome invalid joint %d (max %d)"), joint_num, (ALL_JOINTS-1));
                 return;
             }
 

src/emc/motion/control.c

@@ -273,7 +273,7 @@ void emcmotController(void *arg, long period)
 #ifdef EDEBUG
     dbg_ct++;
 #endif
-    read_homing_in_pins(emcmotConfig->numJoints);
+    read_homing_in_pins(ALL_JOINTS);
     process_inputs();
     do_forward_kins();
     process_probe_inputs();
@@ -287,7 +287,7 @@ void emcmotController(void *arg, long period)
     compute_screw_comp();
     plan_external_offsets();
     output_to_hal();
-    write_homing_out_pins(emcmotConfig->numJoints);
+    write_homing_out_pins(ALL_JOINTS);
     update_status();
     /* here ends the core of the controller */
     emcmotStatus->heartbeat++;
@@ -395,7 +395,7 @@ static void process_inputs(void)
     }
 
     /* read and process per-joint inputs */
-    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+    for (joint_num = 0; joint_num < ALL_JOINTS ; joint_num++) {
 	/* point to joint HAL data */
 	joint_data = &(emcmot_hal_data->joint[joint_num]);
 	/* point to joint data */
@@ -421,7 +421,11 @@ static void process_inputs(void)
 		(joint->backlash_filt + joint->motor_offset);
 	}
 	/* calculate following error */
+	if ( IS_EXTRA_JOINT(joint_num) && get_homed(joint_num) ) {
+	    joint->ferror = 0; // not relevant for homed extrajoints
+	} else {
 	    joint->ferror = joint->pos_cmd - joint->pos_fb;
+	}
 	abs_ferror = fabs(joint->ferror);
 	/* update maximum ferror if needed */
 	if (abs_ferror > joint->ferror_high_mark) {
@@ -548,7 +552,7 @@ static void do_forward_kins(void)
     emcmot_joint_t *joint;
 
     /* copy joint position feedback to local array */
-    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+    for (joint_num = 0; joint_num < NO_OF_KINS_JOINTS; joint_num++) {
 	/* point to joint struct */
 	joint = &joints[joint_num];
 	/* copy feedback */
@@ -660,7 +664,7 @@ static void process_probe_inputs(void)
 	    SET_MOTION_ERROR_FLAG(1);
         }
 
-        for(i=0; i<emcmotConfig->numJoints; i++) {
+        for(i=0; i<NO_OF_KINS_JOINTS; i++) {
             emcmot_joint_t *joint = &joints[i];
 
             if (!GET_JOINT_ACTIVE_FLAG(joint)) {
@@ -729,7 +733,7 @@ static void check_for_faults(void)
         }
     }
     /* check for various joint fault conditions */
-    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+    for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 	/* point to joint data */
 	joint = &joints[joint_num];
 	/* only check active, enabled axes */
@@ -793,7 +797,7 @@ static void set_operating_mode(void)
 #endif
 	/* clear out the motion emcmotDebug->coord_tp and interpolators */
 	tpClear(&emcmotDebug->coord_tp);
-	for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+	for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 	    /* point to joint data */
 	    joint = &joints[joint_num];
 	    /* disable free mode planner */
@@ -835,7 +839,7 @@ static void set_operating_mode(void)
         }
         initialize_external_offsets();
         tpSetPos(&emcmotDebug->coord_tp, &emcmotStatus->carte_pos_cmd);
-	for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+	for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 	    /* point to joint data */
 	    joint = &joints[joint_num];
 	    joint->free_tp.curr_pos = joint->pos_cmd;
@@ -865,7 +869,7 @@ static void set_operating_mode(void)
 	    /* update coordinated emcmotDebug->coord_tp position */
 	    tpSetPos(&emcmotDebug->coord_tp, &emcmotStatus->carte_pos_cmd);
 	    /* drain the cubics so they'll synch up */
-	    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+	    for (joint_num = 0; joint_num < NO_OF_KINS_JOINTS; joint_num++) {
 		/* point to joint data */
 		joint = &joints[joint_num];
 		cubicDrain(&(joint->cubic));
@@ -887,7 +891,7 @@ static void set_operating_mode(void)
 	    if (!emcmotDebug->teleoperating && GET_MOTION_TELEOP_FLAG()) {
 		SET_MOTION_TELEOP_FLAG(0);
 		if (!emcmotDebug->coordinating) {
-		    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+		    for (joint_num = 0; joint_num < NO_OF_KINS_JOINTS; joint_num++) {
 			/* point to joint data */
 			joint = &joints[joint_num];
 			/* update free planner positions */
@@ -906,7 +910,7 @@ static void set_operating_mode(void)
 
 		tpSetPos(&emcmotDebug->coord_tp, &emcmotStatus->carte_pos_cmd);
 		/* drain the cubics so they'll synch up */
-		for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+		for (joint_num = 0; joint_num < NO_OF_KINS_JOINTS; joint_num++) {
 		    /* point to joint data */
 		    joint = &joints[joint_num];
 		    cubicDrain(&(joint->cubic));
@@ -926,7 +930,7 @@ static void set_operating_mode(void)
 	/* check entering free space mode */
 	if (!emcmotDebug->coordinating && GET_MOTION_COORD_FLAG()) {
 	    if (GET_MOTION_INPOS_FLAG()) {
-		for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+		for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 		    /* point to joint data */
 		    joint = &joints[joint_num];
 		    /* set joint planner curr_pos to current location */
@@ -966,7 +970,7 @@ static void handle_jjogwheels(void)
     double distance, pos, stop_dist;
     static int first_pass = 1;	/* used to set initial conditions */
 
-    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+    for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
         double jaccel_limit;
 	/* point to joint data */
 	joint_data = &(emcmot_hal_data->joint[joint_num]);
@@ -1188,7 +1192,7 @@ static void get_pos_cmds(long period)
     int violated_teleop_limit = 0;
 
     /* copy joint position feedback to local array */
-    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+    for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 	/* point to joint struct */
 	joint = &joints[joint_num];
 	/* copy coarse command */
@@ -1207,13 +1211,15 @@ static void get_pos_cmds(long period)
 	/* in free mode, each joint is planned independently */
 	/* initial value for flag, if needed it will be cleared below */
 	SET_MOTION_INPOS_FLAG(1);
-	for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+	for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 	    /* point to joint struct */
 	    joint = &joints[joint_num];
 	    if (!GET_JOINT_ACTIVE_FLAG(joint)) {
 	        /* if joint is not active, skip it */
 	        continue;
             }
+            // extra joint is not managed herein after homing:
+            if (IS_EXTRA_JOINT(joint_num) && get_homed(joint_num)) continue;
 
 	    if(joint->acc_limit > emcmotStatus->acc)
 		joint->acc_limit = emcmotStatus->acc;
@@ -1355,7 +1361,7 @@ static void get_pos_cmds(long period)
 	    if(result == 0)
 	    {
 		/* copy to joint structures and spline them up */
-		for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+		for (joint_num = 0; joint_num < NO_OF_KINS_JOINTS; joint_num++) {
 		    if(!isfinite(positions[joint_num]))
 		    {
                        reportError(_("kinematicsInverse gave non-finite joint location on joint %d"),
@@ -1387,7 +1393,7 @@ static void get_pos_cmds(long period)
 	} // while
 	/* there is data in the interpolators */
 	/* run interpolation */
-	for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+	for (joint_num = 0; joint_num < NO_OF_KINS_JOINTS; joint_num++) {
 	    /* point to joint struct */
 	    joint = &joints[joint_num];
         /* interpolate to get new position and velocity */
@@ -1443,7 +1449,7 @@ static void get_pos_cmds(long period)
 	/* copy to joint structures and spline them up */
 	if(result == 0)
 	{
-	    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+	    for (joint_num = 0; joint_num < NO_OF_KINS_JOINTS; joint_num++) {
 		if(!isfinite(positions[joint_num]))
 		{
 		   reportError(_("kinematicsInverse gave non-finite joint location on joint %d"),
@@ -1483,7 +1489,7 @@ static void get_pos_cmds(long period)
 	/* set position commands to match feedbacks, this avoids
 	   disturbances and/or following errors when enabling */
 	emcmotStatus->carte_pos_cmd = emcmotStatus->carte_pos_fb;
-	for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+	for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 	    /* point to joint struct */
 	    joint = &joints[joint_num];
 	    /* save old command */
@@ -1505,7 +1511,7 @@ static void get_pos_cmds(long period)
 	2) if homing params are wrong then after homing joint pos_cmd are outside,
 	the upstream checks will pass it.
     */
-    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+    for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 	/* point to joint data */
 	joint = &joints[joint_num];
 	/* skip inactive or unhomed axes */
@@ -1526,7 +1532,7 @@ static void get_pos_cmds(long period)
     if ( onlimit ) {
 	if ( ! emcmotStatus->on_soft_limit ) {
 	    /* just hit the limit */
-	    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+	    for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 	        if (joint_limit[joint_num][0] == 1) {
                     joint = &joints[joint_num];
                     reportError(_("Exceeded NEGATIVE soft limit (%.5f) on joint %d\n"),
@@ -1670,7 +1676,7 @@ static void compute_screw_comp(void)
 
 
     /* compute the correction */
-    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+    for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
         /* point to joint struct */
         joint = &joints[joint_num];
 	if (!GET_JOINT_ACTIVE_FLAG(joint)) {
@@ -1934,7 +1940,7 @@ static void output_to_hal(void)
     } else {
         int i;
         double v2 = 0.0;
-        for(i=0; i < emcmotConfig->numJoints; i++)
+        for(i=0; i < ALL_JOINTS; i++)
             if(GET_JOINT_ACTIVE_FLAG(&(joints[i])) && joints[i].free_tp.active)
                 v2 += joints[i].vel_cmd * joints[i].vel_cmd;
         if(v2 > 0.0)
@@ -1988,14 +1994,15 @@ static void output_to_hal(void)
     *(emcmot_hal_data->tooloffset_w) = emcmotStatus->tool_offset.w;
 
     /* output joint info to HAL for scoping, etc */
-    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+    for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 	/* point to joint struct */
 	joint = &joints[joint_num];
+	joint_data = &(emcmot_hal_data->joint[joint_num]);
+
 	/* apply backlash and motor offset to output */
 	joint->motor_pos_cmd =
 	    joint->pos_cmd + joint->backlash_filt + joint->motor_offset;
 	/* point to HAL data */
-	joint_data = &(emcmot_hal_data->joint[joint_num]);
 	/* write to HAL pins */
 	*(joint_data->motor_offset) = joint->motor_offset;
 	*(joint_data->motor_pos_cmd) = joint->motor_pos_cmd;
@@ -2031,7 +2038,17 @@ static void output_to_hal(void)
              *(joint_data->unlock) = 0;
         }
 
-    } //for joint_num
+	if (IS_EXTRA_JOINT(joint_num) && get_homed(joint_num)) {
+	    // passthru posthome_cmd with motor_offset
+	    // to hal pin: joint.N.motor-pos-cmd
+	    extrajoint_hal_t *ejoint_data;
+	    int e = joint_num - NO_OF_KINS_JOINTS;
+	    ejoint_data = &(emcmot_hal_data->ejoint[e]);
+	    *(joint_data->motor_pos_cmd) = *(ejoint_data->posthome_cmd)
+	                                 + joint->motor_offset;
+	    continue;
+	}
+    } // for joint_num
 
     /* output axis info to HAL for scoping, etc */
     for (axis_num = 0; axis_num < EMCMOT_MAX_AXIS; axis_num++) {
@@ -2067,7 +2084,7 @@ static void update_status(void)
 
     /* copy status info from private joint structure to status
        struct in shared memory */
-    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+    for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 	/* point to joint data */
 	joint = &joints[joint_num];
 	/* point to joint status */

src/emc/motion/emcmotcfg.h

@@ -20,7 +20,13 @@
 /* number of joints supported
    Note: this is not a global variable but a compile-time parameter
    since it sets array sizes, etc. */
+
+// total number of joints available (kinematics_joints + extra_joints)
 #define EMCMOT_MAX_JOINTS 16
+
+// number of extra joints (NOT used in kinematics calculations):
+#define EMCMOT_MAX_EXTRAJOINTS EMCMOT_MAX_JOINTS
+
 /* number of axes defined by the interp */ //FIXME: shouldn't be here..
 #define EMCMOT_MAX_AXIS 9
 

src/emc/motion/homing.c

@@ -182,15 +182,15 @@ static void update_home_is_synchronized(void) {
     int jno,joint_num;
 
     // first, clear all H[*].home_is_synchronized
-    for (jno = 0; jno < emcmotConfig->numJoints; jno++) {
+    for (jno = 0; jno < ALL_JOINTS; jno++) {
         H[jno].home_is_synchronized = 0;
     }
-    for (jno = 0; jno < emcmotConfig->numJoints; jno++) {
+    for (jno = 0; jno < ALL_JOINTS; jno++) {
         if (H[jno].home_sequence < 0) {
             H[jno].home_is_synchronized = 1;
             continue;
         }
-        for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+        for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
             if (joint_num == jno) continue;
             if (   (    H[joint_num].home_sequence < 0)
                 && (ABS(H[joint_num].home_sequence) == H[jno].home_sequence) )  {
@@ -397,7 +397,7 @@ void do_homing_sequence(void)
 
     case HOME_SEQUENCE_DO_ONE_JOINT:
         // Expect one joint with home_state==HOME_START
-        for (i=0; i < emcmotConfig->numJoints; i++) {
+        for (i=0; i < ALL_JOINTS; i++) {
             joint = &joints[i];
             if (H[i].home_state == HOME_START) {
                H[i].joint_in_sequence = 1;
@@ -419,7 +419,7 @@ void do_homing_sequence(void)
         // Determine home_sequence and set H[i].joint_in_sequence
         // based on home_state[i] == HOME_START
         if (!sequence_is_set) {
-            for (i=0; i < emcmotConfig->numJoints; i++) {
+            for (i=0; i < ALL_JOINTS; i++) {
                 joint = &joints[i];
                 if (H[i].home_state == HOME_START) {
                     if (   sequence_is_set
@@ -465,7 +465,7 @@ void do_homing_sequence(void)
         for(i=0; i < MAX_HOME_SEQUENCES; i++) {
             H[i].sync_final_move = 0; //reset to allow a rehome
         }
-        for(i=0; i < emcmotConfig->numJoints; i++) {
+        for(i=0; i < ALL_JOINTS; i++) {
             if (!H[i].joint_in_sequence) continue;
             joint = &joints[i];
             if (   (H[i].home_flags & HOME_NO_REHOME)
@@ -478,7 +478,7 @@ void do_homing_sequence(void)
             if (H[i].home_sequence < 0) {
                 // if a H[i].home_sequence is neg, find all joints that
                 // have the same ABS sequence value and make them the same
-                for(ii=0; ii < emcmotConfig->numJoints; ii++) {
+                for(ii=0; ii < ALL_JOINTS; ii++) {
                     if (H[ii].home_sequence == ABS(H[i].home_sequence)) {
                         H[ii].home_sequence =      H[i].home_sequence;
                     }
@@ -489,14 +489,14 @@ void do_homing_sequence(void)
         *                          synchronize all joints final move
         */
         special_case_sync_all = 1; // disprove
-        for(i=0; i < emcmotConfig->numJoints; i++) {
+        for(i=0; i < ALL_JOINTS; i++) {
             joint = &joints[i];
             if (H[i].home_sequence != -1) {special_case_sync_all = 0;}
         }
         if (special_case_sync_all) {
             home_sequence = 1;
         }
-	for(i=0; i < emcmotConfig->numJoints; i++) {
+	for(i=0; i < ALL_JOINTS; i++) {
             if (!H[i].joint_in_sequence) continue;
 	    joint = &joints[i];
 	    if  ( H[i].home_state != HOME_IDLE && H[i].home_state != HOME_START) {
@@ -511,7 +511,7 @@ void do_homing_sequence(void)
 
     case HOME_SEQUENCE_START_JOINTS:
 	/* start all joints whose sequence number matches home_sequence */
-	for(i=0; i < emcmotConfig->numJoints; i++) {
+	for(i=0; i < ALL_JOINTS; i++) {
 	    joint = &joints[i];
 	    if(ABS(H[i].home_sequence) == home_sequence) {
                 if (!H[i].joint_in_sequence) continue;
@@ -532,7 +532,7 @@ void do_homing_sequence(void)
 	break;
 
     case HOME_SEQUENCE_WAIT_JOINTS:
-	for(i=0; i < emcmotConfig->numJoints; i++) {
+	for(i=0; i < ALL_JOINTS; i++) {
             if (!H[i].joint_in_sequence) continue;
 	    joint = &joints[i];
             // negative H[i].home_sequence means sync final move
@@ -584,7 +584,7 @@ void do_homing(void)
 	return;
     }
     /* loop thru joints, treat each one individually */
-    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+    for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
         if (!H[joint_num].joint_in_sequence) continue;
 	/* point to joint struct */
 	joint = &joints[joint_num];
@@ -1147,7 +1147,7 @@ void do_homing(void)
                         int jno;
                         emcmot_joint_t *jtmp;
                         H[home_sequence].sync_final_move = 1; //disprove
-                        for (jno = 0; jno < emcmotConfig->numJoints; jno++) {
+                        for (jno = 0; jno < ALL_JOINTS; jno++) {
                             jtmp = &joints[jno];
                             if (!H[jno].joint_in_sequence) continue;
                             if (ABS(H[jno].home_sequence) != home_sequence) {continue;}

src/emc/motion/mot_priv.h

@@ -1,4 +1,4 @@
-/********************************************************************
+/*******************************************************************
 * Description: mot_priv.h
 *   Macros and declarations local to the realtime sources.
 *
@@ -115,6 +115,10 @@ typedef struct {
     hal_bit_t   *jjog_vel_mode;	/* RPI: true for "velocity mode" jogwheel */
 } joint_hal_t;
 
+typedef struct {
+    hal_float_t *posthome_cmd; //  IN pin extrajoint
+} extrajoint_hal_t;
+
 typedef struct {
     hal_float_t *pos_cmd;        /* RPI: commanded position */
     hal_float_t *teleop_vel_cmd; /* RPI: commanded velocity */
@@ -199,6 +203,7 @@ typedef struct {
 
     spindle_hal_t spindle[EMCMOT_MAX_SPINDLES];     /*spindle data */
     joint_hal_t joint[EMCMOT_MAX_JOINTS];	/* data for each joint */
+    extrajoint_hal_t ejoint[EMCMOT_MAX_EXTRAJOINTS]; /* data for each extrajoint */
     axis_hal_t axis[EMCMOT_MAX_AXIS];	        /* data for each axis */
 
     hal_bit_t   *eoffset_active; /* ext offsets active */
@@ -234,6 +239,19 @@ extern struct emcmot_config_t *emcmotConfig;
 extern struct emcmot_debug_t *emcmotDebug;
 extern struct emcmot_error_t *emcmotError;
 
+
+// total number of joints (typically set with [KINS]JOINTS)
+#define ALL_JOINTS emcmotConfig->numJoints
+
+// number of kinematics-only joints:
+#define NO_OF_KINS_JOINTS (ALL_JOINTS - emcmotConfig->numExtraJoints)
+
+#define IS_EXTRA_JOINT(jno) (jno >= NO_OF_KINS_JOINTS)
+
+// 0-based Joint numbering:
+// kinematic-only jno.s: [0                 ... (NO_OF_KINS_JOINTS -1) ]
+// extrajoint     jno.s: [NO_OF_KINS_JOINTS ... (ALL_JOINTS  -1) ]
+
 /***********************************************************************
 *                    PUBLIC FUNCTION PROTOTYPES                        *
 ************************************************************************/

src/emc/motion/motion.c

@@ -51,7 +51,9 @@ static int num_spindles = 1; /* default number of spindles is 1 */
 RTAPI_MP_INT (num_spindles, "number of spindles");
 int motion_num_spindles;
 static int num_joints = EMCMOT_MAX_JOINTS;	/* default number of joints present */
-RTAPI_MP_INT(num_joints, "number of joints");
+RTAPI_MP_INT(num_joints, "number of joints used in kinematics");
+static int num_extrajoints = 0;	/* default number of extra joints present */
+RTAPI_MP_INT(num_extrajoints, "number of extra joints (not used in kinematics)");
 static int num_dio = DEFAULT_DIO;	/* default number of motion synched DIO */
 RTAPI_MP_INT(num_dio, "number of digital inputs/outputs");
 static int num_aio = DEFAULT_AIO;	/* default number of motion synched AIO */
@@ -118,7 +120,12 @@ static int mot_comp_id;	/* component ID for motion module */
 static int init_hal_io(void);
 
 /* functions called by init_hal_io() */
+
+// halpins for ALL joints (kinematic joints and extra joints):
 static int export_joint(int num,           joint_hal_t * addr);
+// additional halpins for extrajoints:
+static int export_extrajoint(int num, extrajoint_hal_t * addr);
+
 static int export_axis(char c, axis_hal_t  * addr);
 static int export_spindle(int num, spindle_hal_t * addr);
 
@@ -157,7 +164,7 @@ void switch_to_teleop_mode(void) {
         }
     }
 
-    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+    for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
         joint = &joints[joint_num];
         if (joint != 0) { joint->free_tp.enable = 0; }
     }
@@ -218,6 +225,23 @@ int rtapi_app_main(void)
 	return -1;
     }
 
+    if (( num_extrajoints < 0 ) || ( num_extrajoints > num_joints )) {
+	rtapi_print_msg(RTAPI_MSG_ERR,
+	    _("\nMOTION: num_extrajoints is %d, must be between 0 and %d\n\n"), num_extrajoints, num_joints);
+	hal_exit(mot_comp_id);
+	return -1;
+    }
+    if ( (num_extrajoints > 0) && (kinematicsType() != KINEMATICS_BOTH) ) {
+	rtapi_print_msg(RTAPI_MSG_ERR, _("\nMOTION: nonzero num_extrajoints requires KINEMATICS_BOTH\n\n"));
+        return -1;
+    }
+    if (num_extrajoints > 0) {
+	rtapi_print_msg(RTAPI_MSG_ERR,
+            _("\nMOTION: kinematicjoints=%2d\n            extrajoints=%2d\n           Total joints=%2d\n\n"),
+            num_joints-num_extrajoints, num_extrajoints, num_joints
+            );
+    }
+
     if (( num_spindles < 0 ) || ( num_spindles > EMCMOT_MAX_SPINDLES )) {
 	rtapi_print_msg(RTAPI_MSG_ERR,
 	    _("MOTION: num_spindles is %d, must be between 0 and %d\n"), num_spindles, EMCMOT_MAX_SPINDLES);
@@ -312,6 +336,7 @@ static int init_hal_io(void)
 {
     int n, retval;
     joint_hal_t      *joint_data;
+    extrajoint_hal_t *ejoint_data;
     axis_hal_t       *axis_data;
 
     rtapi_print_msg(RTAPI_MSG_INFO, "MOTION: init_hal_io() starting...\n");
@@ -455,7 +480,6 @@ static int init_hal_io(void)
 
     /* export joint pins and parameters */
     for (n = 0; n < num_joints; n++) {
-	/* point to axis data */
 	joint_data = &(emcmot_hal_data->joint[n]);
 	/* export all vars */
         retval = export_joint(n, joint_data);
@@ -475,6 +499,16 @@ static int init_hal_io(void)
         rtapi_print_msg(RTAPI_MSG_ERR, _("MOTION: export_joint_home_pins failed\n"));
         return -1;
     }
+    /* export joint pins and parameters */
+    for (n = 0; n < num_extrajoints; n++) {
+        ejoint_data = &(emcmot_hal_data->ejoint[n]);
+        retval = export_extrajoint(n + num_joints - num_extrajoints,ejoint_data);
+        if (retval != 0) {
+            rtapi_print_msg(RTAPI_MSG_ERR, _("MOTION: ejoint %d pin/param export failed\n"), n);
+            return -1;
+        }
+    }
+
     /* export axis pins and parameters */
     for (n = 0; n < EMCMOT_MAX_AXIS; n++) {
         char c = "xyzabcuvw"[n];
@@ -626,6 +660,15 @@ static int export_joint(int num, joint_hal_t * addr)
     return 0;
 }
 
+static int export_extrajoint(int num, extrajoint_hal_t * addr)
+{
+    int retval;
+    /* export extrajoint pins */
+    if ((retval = hal_pin_float_newf(HAL_IN,  &(addr->posthome_cmd),  mot_comp_id,
+                                            "joint.%d.posthome-cmd",  num)) != 0) return retval;
+    return 0;
+}
+
 static int export_axis(char c, axis_hal_t * addr)
 {
     int retval, msg;
@@ -713,7 +756,11 @@ static int init_comm_buffers(void)
     SET_MOTION_TELEOP_FLAG(0);
     emcmotDebug->split = 0;
     emcmotStatus->heartbeat = 0;
-    emcmotConfig->numJoints = num_joints;
+
+    ALL_JOINTS                 = num_joints;      // emcmotConfig->numJoints from [KINS]JOINTS
+    emcmotConfig->numExtraJoints = num_extrajoints; // from motmod num_extrajoints=
+    emcmotStatus->numExtraJoints = num_extrajoints;
+
     emcmotConfig->numSpindles = num_spindles;
     emcmotConfig->numDIO = num_dio;
     emcmotConfig->numAIO = num_aio;
@@ -761,7 +808,7 @@ static int init_comm_buffers(void)
       axis->locking_joint = -1;
    }
     /* init per-joint stuff */
-    for (joint_num = 0; joint_num < emcmotConfig->numJoints; joint_num++) {
+    for (joint_num = 0; joint_num < ALL_JOINTS; joint_num++) {
 	/* point to structure for this joint */
 	joint = &joints[joint_num];
 
@@ -965,7 +1012,7 @@ static int setTrajCycleTime(double secs)
     tpSetCycleTime(&emcmotDebug->coord_tp, secs);
 
     /* set the free planners, cubic interpolation rate and segment time */
-    for (t = 0; t < emcmotConfig->numJoints; t++) {
+    for (t = 0; t < ALL_JOINTS; t++) {
 	cubicSetInterpolationRate(&(joints[t].cubic),
 	    emcmotConfig->interpolationRate);
     }
@@ -996,7 +1043,7 @@ static int setServoCycleTime(double secs)
 	(int) (emcmotConfig->trajCycleTime / secs + 0.5);
 
     /* set the cubic interpolation rate and PID cycle time */
-    for (t = 0; t < emcmotConfig->numJoints; t++) {
+    for (t = 0; t < ALL_JOINTS; t++) {
 	cubicSetInterpolationRate(&(joints[t].cubic),
 	    emcmotConfig->interpolationRate);
 	cubicSetSegmentTime(&(joints[t].cubic), secs);

src/emc/motion/motion.h

@@ -675,7 +675,7 @@ Suggestion: Split this in to an Error and a Status flag register..
 	unsigned char tail;	/* flag count for mutex detect */
 	int external_offsets_applied;
 	EmcPose eoffset_pose;
-        
+	int numExtraJoints;
     } emcmot_status_t;
 
 /*********************************
@@ -706,9 +706,12 @@ Suggestion: Split this in to an Error and a Status flag register..
 
 	int config_num;		/* Incremented everytime configuration
 				   changed, should match status.config_num */
-	int numJoints;		/* The number of joints in the system (which
+	int numJoints;		/* The number of total joints in the system (which
 				   must be between 1 and EMCMOT_MAX_JOINTS,
-				   inclusive). Can be changed at insmod time */
+				   inclusive). includes extra joints*/
+	int numExtraJoints;		/* The number of extra joints in the system (which
+				   must be between 1 and EMCMOT_MAX_EXTRAJOINTS,
+				   inclusive). */
 	int numSpindles; /* The number of spindles, 1 to EMCMOT_MAX_SPINDLES */
 
 	KINEMATICS_TYPE kinType;

src/emc/nml_intf/emc_nml.hh

@@ -1223,6 +1223,7 @@ class EMC_MOTION_STAT:public EMC_MOTION_STAT_MSG {
     int on_soft_limit;
     int external_offsets_applied;
     EmcPose eoffset_pose;
+    int numExtraJoints;
 };
 
 // declarations for EMC_TASK classes

src/emc/task/taskintf.cc

@@ -1973,6 +1973,8 @@ int emcMotionUpdate(EMC_MOTION_STAT * stat)
 	stat->analog_output[aio] = emcmotStatus.analog_output[aio];
     }
 
+    stat->numExtraJoints=emcmotStatus.numExtraJoints;
+
     // set the status flag
     error = 0;
     exec = 0;

src/emc/usr_intf/axis/extensions/emcmodule.cc

@@ -362,6 +362,7 @@ static PyMemberDef Stat_members[] = {
     {(char*)"feed_override_enabled", T_BOOL, O(motion.traj.feed_override_enabled), READONLY},
     {(char*)"adaptive_feed_enabled", T_BOOL, O(motion.traj.adaptive_feed_enabled), READONLY},
     {(char*)"feed_hold_enabled", T_BOOL, O(motion.traj.feed_hold_enabled), READONLY},
+    {(char*)"num_extrajoints", T_INT, O(motion.numExtraJoints), READONLY},
 
 
 // EMC_SPINDLE_STAT motion.spindle

src/emc/usr_intf/axis/scripts/axis.py

@@ -930,6 +930,15 @@ class LivePlotter:
         widgets.code_text.insert("end", codes)
         widgets.code_text.configure(state="disabled")
 
+        # disable jog radiobutton for extrajoints that are homed
+        # since control is transferred to joint.N.posthome-cmd
+        for jno in range(num_joints - self.stat.num_extrajoints, num_joints):
+            jname = tabs_manual+".joints.joint"+str(jno)
+            #print jno,num_joints,num_extrajoints,s.homed[jno],jname
+            if s.homed[jno]: state="disabled"
+            else:            state="normal"
+            root_window.call(jname,"configure","-state",state)
+
         user_live_update()
 
     def clear(self):
@@ -2611,7 +2620,6 @@ class TclCommands(nf.TclCommands):
             go_home(-1)
 
     def unhome_all_joints(event=None):
-        if not manual_ok(): return
         ensure_mode(linuxcnc.MODE_MANUAL)
         set_motion_teleop(0)
         c.unhome(-1)