ADLINK Technology PCI-8102, User Manual, Page: 82 / 210

72 Operation Theory
speed command will be set. If the error counter is zero, it means
that zero motor speed command will be set.
At following four situations, the ERC signal will be outputted auto-
matically from motion controller to motor driver in order to clear
error counter at the same time.
1. Home return is complete
2. The end-limit switch is touched
3. An alarm signal is active
4. An emergency stop command is issued
4.3.6 Servo ON/OFF Switch
The servo on/off switch is a general digital output signal on motion
controller. We define it as SVON pin on the connector. It can be
used for switching motor driver’s controlling state. Once it is
turned on, the motor will be holded because the control loop of
driver is active. Be careful that when the axis is vertically installed
and the servo signal is turned off, the axis will be in uncontrolled
state. It could be falled down on the ground. Some situations like
servo alarm and emergeny signal ON will result in the same trou-
ble.
4.3.7 Servo Ready Signal
The servo ready signal is a general digital input on motion control-
ler. It has no relative purpose to motion controller. Users can con-
nect this signal to motor driver’s RDY signal to check if the motor
driver is in ready state. It lets users to check something like the
motor driver’s power has been inputed or not. Or users can con-
nect this pin as a general input for other purpose. It doesn’t affect
motion control.
4.3.8 Servo Alarm Reset Switch
The servo driver will raise an alarm signal if there is something
wrong inside the servo driver. Some alarm situations like servo
motor over current, over speed, over loading and so on. Power
reset can clear the alarm status but users usually don’t want to
power off the servo motor when operating. There is one pin from