
B–63443EN/02
18. SPINDLE FUNCTIONS
PMC INTERFACE
197
The speed arrival signal SAR informs the CNC that the spindle speed has
reached the commanded speed. The CNC uses this signal as the cutting
start condition. The PMC side should turn this signal to “1” when the
actual speed reaches the commanded speed. When the SAR signal is not
used, parameter SAR No. 3708#0 should be set to 0.
The SAR is checked under the following conditions:
(1) Before starting distribution of the first feed (move command) block
after shifting from the rapid traverse to the cutting feed. This checking
is performed after the time set by parameter no. 3740 has elapsed after
the feed block is read.
(2) Before starting distribution of the first feed command block after an
S code is commanded. The wait time for checking is the same as in
item (1).
(3) When an S code and feed are programmed in the same block, the S
code (or analog voltage) is output, and the SAR signal is checked after
a fixed time elapses. If the SAR signal is set to “1”, feed begins.
NOTE
According to the conditions of item (3) above, note that if the
circuit is so designed that SAR is turned to “0”
simultaneously with the output of an S code and the change
of spindle speed is gated with DEN signal, the operation will
stop. That is, the spindle speed does not reach the
commanded speed because the CNC is waiting for the DEN
signal and distribution is not started because the CNC is
waiting for the SAR signal.
18.2
SPEED ARRIVAL
SIGNAL (INPUT) SAR
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