ADLINK PCI-8158 - Manual (Page 82)

72 Operation Theory
on, the motor will be held 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 and
it can fall. Some situations, such as a servo alarm and emergency
signal ON may result in the same state.
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. You can connect
this signal to motor driver’s RDY signal to check if the motor driver
is in ready state. It lets you check if, for example, the motor driver’s
power has been input or not. Or, users can connect this pin as a
general input for other purpose and it does not affect motion con-
trol.
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 include servo
motor over current, over speed, over loading, etc. Power reset can
clear the alarm status but you usually don’t want to power off the
servo motor when operating. There is one pin from servo driver for
users to reset the alarm status. Our motion controller provides one
general output pin for each axis. You can use this pin for resetting
servo alarm status.
4.4 Mechanical switch interface
We provide some dedicated input pins for mechanical switches
like original switch (ORG), plus and minus end-limit switch (
±
EL),
slow down switch (SD), positioning start switch (PCS), counter
latch switch (LTC), emergency stop input (EMG) and counter
clear switch (CLR). These switches’ response time is very short,
only a few ASIC clock cycles. There is no real-time problem when
using these signals. All functions are done by the motion ASIC.
The software does not need to do anything and only needed to
wait on the results.