1768-M04SE Error

I stopped by to look at a problem with a new machine, the machine uses a AB compactlogix processor and two 1768-M04SE SERCOS modules for communication with the servo drives. The machine would not start, indicating a fault with one of the servo motors however I noticed that the I/O light was flashing green on the processor and both 1768-M04SE modules displayed the following code:

CP Light - Solid Orange
Ring Light - Off
OK Light - Flashing green

I have not been able to find information with regard to this exact error code, has anyone encountered this error before?

From the manual.

http://samplecode.rockwellautomation.com/idc/groups/literature/documents/in/1768-in005_-en-p.pdf

Look for cables that are broken, unplugged, or in the
wrong port.

Check the drives for faults.

Mark