35 lines
1.5 KiB
Text
35 lines
1.5 KiB
Text
.TH rtapi_clock_set_period "3rtapi" "2006-10-12" "LinuxCNC Documentation" "RTAPI"
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.SH NAME
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rtapi_clock_set_period \- set the basic time interval for realtime tasks
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.SH SYNTAX
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.HP
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rtapi_clock_set_period(long int \fInsec\fR)
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.SH ARGUMENTS
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.IP \fInsec\fB
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The desired basic time interval for realtime tasks.
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.SH DESCRIPTION
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\fBrtapi_clock_set_period\fR sets the basic time interval for realtime tasks.
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All periodic tasks will run at an integer multiple of this period. The first
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call to \fBrtapi_clock_set_period\fR with \fInsec\fR greater than zero will
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start the clock, using \fInsec\fR as the clock period in nano-seconds. Due to
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hardware and RTOS limitations, the actual period may not be exactly what was
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requested. On success, the function will return the actual clock period if it
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is available, otherwise it returns the requested period. If the requested
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period is outside the limits imposed by the hardware or RTOS, it returns
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\fB-EINVAL\fR and does not start the clock. Once the clock is started,
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subsequent calls with non-zero \fInsec\fR return \fB-EINVAL\fR and have no
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effect. Calling \fBrtapi_clock_set_period\fR with \fInsec\fR set to zero
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queries the clock, returning the current clock period, or zero if the clock has
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not yet been started.
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.SH REALTIME CONSIDERATIONS
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Call only from within init/cleanup code, not from realtime tasks. This
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function is not available from user (non-realtime) code.
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.SH RETURN VALUE
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The actual period provided by the RTOS, which may be different than the
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requested period, or a RTAPI status code.
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