How to check SV0401 alarm 

Although the ready signal (PRDY) of the position control was ON,
the ready signal (VRDY) on the velocity control was OFF.
need to check CX4 hard wiring and relays (relay number is different depend on machine)
Check for any interlocks, feedhold conditions, ESTOP conditions on the ladder.
Check for any alarms on SVMs.
Please check EMG terminal block on PCB also.
(XEMG ??)