ADLINK Technology PCI-8102, User Manual, Page: 81 / 210

Operation Theory 71
4.3.4 Servo Alarm Signal
The alarm signal is an output signal from motor driver. It tells
motion controller that there has something error inside servo
motor or driver. Once the motion controller receives this signal, the
pulses command will stop sending and the status of ALM signal
will be ON. The reasons of alarm could be servo motor’s over
speed, over current, over loaded and so on. Please check motor
driver’s manual about the details.
The logic of alarm signal must be set correctly. If the alarm logic’s
setting is not the same as motor driver’s setting, the ALM status
will be always ON and the pulse command can never be output-
ted.
4.3.5 Error Clear Signal
The ERC signal is an output from the motion controller. It tells
motor driver to clear the the error counter. The error counter is
counted from the difference of command pulses and feedback
pulses. The feedback position will always have a delay from the
command position. It results in pulse differences between these
two positions at any moment. The differences are shown in error
counter. Motor driver uses the error counter as a basic control
index. The large the error counter value is, the faster the motor