Rockwell Automation 57C422B 2 Axis Servo Module - Manual (Page 65)

PROGRAMMING 4-37
4.38 Register 73: Fault
Register 73 is the fault register. This register is updated
continuously by the module except during an auto-tune
operation, when it will not be updated until the end of the
sequence. This register is read-only. Refer to figure 4.37.
See 4.49 for more information on causing interrupts on the
corresponding errors.
The overtravel and drive fault bits can only be set if they are
first enabled in register 2.
The maximum position error exceeded bit is set when the
following error in register 80 has exceeded the maximum
Figure 4.37 – Fault Register