
B–63523EN–1/03
2. PREPARATIONS FOR OPERATION
454
The servo axis and spindle motor speeds are monitored. If the speed of
an axis exceeds a preset maximum (specified by parameter setting), the
corresponding signal is output to a Y address (specified by parameter
setting) of the PMC.
(1)Setting a Y address for signal output
In parameter No. 1891, set a Y byte address to which signals are to be
output. (See Signal Address section for format)
(2)Setting a maximum speed
Set the maximum speed for each servo–motor–controlled axis in
parameter No. 1890.
Set the maximum speed for the axis controlled by the first serial
spindle motor in S1 of parameter No. 4345.
Set the maximum speed for the axis controlled by the second serial
spindle motor in S2 of parameter No. 4345.
When 0 is specified as the maximum speed for an axis, the speed of
that axis is not monitored.
(3)Signal input
Set the motor speed detection function enable signal MSDFON to 1.
When the power is turned on, the CNC checks the status of this signal.
If the signal is 1, the CNC enables the motor speed detection function.
When MSDFON is 1, and a motor speed exceeds the preset maximum,
the corresponding bit of the set Y address is set to 1.
The following diagram illustrates the signal output timing.
Speed
Command for axis
Actual motor speed
? min
–1
(Preset maximum)
Time
Max 2msec (servo motor)
Max 10msec (spindle motor)
Max 16msec
CNC output signal
<Y????#?>
NOTE
The status of each signal is updated every 8 msec.
(Fluctuations in real speed of less than 8 msec duration
cannot be detected.)
2.11
SERVO/SPINDLE
MOTOR SPEED
DETECTION
General