Parker Hannifin 
  Troubleshooting   151 
PROBLEM  CAUSE / VERIFICATION  SOLUTION 
Axis Status LED 
Axis status LED is not 
on 
Axis is disabled with no fault (normal state for 
steppers or servo motors). 
Enable drive. 
Axis status LED is red  Axis fault. Motion on this axis is disabled during a 
fault state. 
NOTE: The LED illuminates red whenever the drive 
fault input is activated (drive faulted, no axis cable 
connected, etc.) 
Check for faulted drive. Enable drive. (Refer to Operation
 
section of this table.) 
Check for axis cable disconnected. 
CANopen LED 
CANopen LED is red, 
single flash 
Excess bus errors: At least one CAN controller error 
counter has reached or exceeded the warning level 
(too many error frames). 
The controller chip has too many bus errors. One possible 
reason would be incorrect bit rate on one or more modules. 
Error control event: guard event (NMT-slave or NMT-
master) has occurred. 
CANopen LED is red, 
double flash 
Error control event: heartbeat event (heartbeat 
consumer) has occurred. 
Health Event: A node has stopped sending heartbeat or node 
guard responses. The errant node will have a node state of 0 
(dead). One possible reason would be node received overrun 
caused by a cyclic period that is too fast for the node. 
Another possible reason is the connection between the master 
and slave has been severed. 
 
CANopen LED is red, 
triple flash 
Sync error: SYNC message has not been received 
within the configured communication cycle period 
timeout. 
Object 0x1006 contains the sync cycle period in ms. The sync 
cycle period time out should be the configured sync cycle 
period multiplied by 1.5. 
CANopen LED is off  Controller is executing a reset.  This is not a problem unless the controller is finished executing 
a reset. If the LED does not turn on after a reset, check the 
connection to the controller. 
Ethernet Status LED 
Ethernet link/activity: 
yellow LED is off 
No Ethernet link is detected.  Check for the correct type of cable. 
Verify the cable pinout matches the ACR90x0. (See the section 
“Ethernet and ETHERNET Powerlink Connectors” in Chapter 2, 
Specifications, of the ACR9000 Hardware Installation Guide.) 
Ethernet speed: green 
LED is flashing  
Ethernet port is getting intermittent 10Mbps and 
100Mbps connection. 
Verify the Ethernet card in the PC is functioning correctly. 
Verify the ACR controller Ethernet port is functioning correctly.