In SSRF beamline control we use the autosave module to
save the 'DVAL' field and restore the value of a motor position when
Recently we encountered a problem.
Sometimes one of the controllers(MAXv-8000) in a VME
crate crashes while the IOC(mvme5500) still runs. Because the
motor channel is still connected, the system looks OK. In this case if
changing the ‘DVAL’ field to drive the motor, the controller doesn’t response
and the ‘DRBV’ of the motor keeps unchanged. So the saved value
'DVAL' isn't no long the motor real position.
When hard rebooting the VME crate, the
'DRBV' set by the recovered 'DVAL' doesn't match the motor real
Are there some problems in our saving and restoring
method? How to deal with this kind of problem?
Any suggestion will be greatly appreciated!
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Shanghai Institute of Applied Physics CAS