
11.APPLYCATION OF OTHER FUNCTIONS B-63494EN/02
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11.3 SPINDLE OUTPUT CONTROL BY THE PMC
11.3.1 Overview
The dual check safety function uses the CNC CPU and spindle DSP to
separately monitor the spindle speed (safe speed monitoring function).
When one or more spindles have a speed greater than or equal to the
safe speed in safe signal mode B (in a state where a guard open
request is input and the guard is closed), the guard lock cancellation
signal *LGD is set to 0 to disallow the cancellation of guard lock.
When one or more axes have a speed greater than or equal to the safe
speed in safe signal mode C (in a state where a guard open request is
input and the guard is open), spindle alarm 757 (767) or 9069 (or
7n69) occurs and power to the motor driving circuit is interrupted.
Spindle output control by PMC is a function for controlling the speed
and polarity of spindle motor rotation of each spindle connected by
the spindle serial output/spindle analog output option.
The dual check safety function and spindle output control by PMC can
be used to construct a machine that operates as shown below.
• Automatically reduces the spindle speed to less than or equal to
the safe speed in safe signal mode B to allow the opening of the
guard.
• Limits the spindle speed within the safe speed in safe signal
mode C to prevent an alarm from being issued by the safe speed
monitoring function.
For speed control of the feed axis, see Section 11.2, "EXTERNAL
DECELERATION."