
B–62073E–1/04 2. INTERFACE BETWEEN CNC AND PMC–NA OR NB
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(a) Spindle speed fluctuation alarm signal (SPAL)
[Classification]
Output signal
[Function] This signal informs that the actual spindle speed fluctuation exceeds the allowable fluctuation
range for the specified speed.
[Output Condition]
This signal is turned on when:
i. The actual spindle speed is higher than the maximum or lower than the minimum allow-
able speed for the specified speed. When automatic operation is being started, this sig-
nal (SPAL) performs automatic operation for a single block and stops the operation. The
control unit does not reduce the output voltage to the spindle amplifier to zero when SPAL
is turned on. The control unit outputs voltage in accordance with spindle motor command
voltage signals RI0 to RI12. Therefore, when SPAL is turned on, the PMC turns off all
spindle motor command voltage signals RI0 to RI12.
This signal is turned off when:
i. The alarm for spindle speed fluctuation is not detected
ii. The control unit is reset with this signal on and the alarm is terminated