Experimental Physics and
Industrial Control System

Hi，everybody,

 

In SSRF beamline control we use the autosave module to save the 'DVAL' field and restore the value of a motor position when rebooting.

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 position.

 

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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Zhang Zhaohong（张招红）
No.239 Zhangheng Road
PuDong District
Shanghai Institute of Applied Physics CAS
Shanghai, China
Tel: +86-21-33933238