Experimental Physics and
Industrial Control System

Hi Pete,

 

What you are describing should never occur, and I have never seen it in many years of working with the motor record on many types of controllers.  The last step in your sequence is:

IOC re-started, save restore writes previous positions into motor driver, causing them to move to that position, and havoc!

 

What should happen is that save restore restores the positions into the motor record in the phase 0, before the motor record will move anything.  Thus it just sets the position in the controller, it does not cause a move.

 

One explanation for what you are observing is that you have motor VAL field in the wrong autosave set.  There are typically 2 autosave request files for an IOC that has motors.  auto_positions.req saves the motor DVAL and OFF fields.  auto_settings.req saves everthing else, like .DHLM, .VELO (perhaps), etc.  These 2 request files generate 2 different .sav files, auto_positions.sav and auto_settings.sav.  The autosave configuration file then has lines like this:

 

set_pass0_restoreFile("auto_positions.sav")

set_pass0_restoreFile("auto_settings.sav")

set_pass1_restoreFile("auto_settings.sav")

 

Note that auto_positions.sav is only restored on pass 0. During that pass autosave cannot cause the motor to actually move, it just sets the DVAL position in the record, which then gets pushed to the controller in set mode.

 

Is what I describe above how you have your motor autosave values configured?

 

If so, then what type of controller are you seeing this issue with, and is it reproducible?

 

Mark