Experimental Physics and
Industrial Control System

Mark Rivers <[email protected]> · Thu, 5 Sep 2013 19:58:03 +0000

The problem is that synchronous puts to the motor record wait for the motor to stop moving, or the timeout (10 seconds default) to occur.  You don't want to use SYNC here.

Mark

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Konrad, Martin
Sent: Thursday, September 05, 2013 2:55 PM
To: [email protected]; [email protected]
Subject: seq and synchronous writes

Hello,
I am using a state machine to control a motor setup. In each step it 
basically sends a command to the motor record and waits for it to 
complete. This can be detected by the "done moving" field (DMOV).

Here is how I implemented this:

state1 {
   entry {
     sprintf(stateMsg, "state 1");
     pvPut(stateMsg);
   }

   when(foo) {
     motor = bar;
     pvPut(motor, SYNC);
   } state state2
}

state2 {
   entry {
     sprintf(stateMsg, "state 2");
     pvPut(stateMsg);
   }
}

Unfortunately this leads to a long delay between the motor starting to 
move and the update of the status message (sometimes 10 seconds!).

I suspect I'm using sequencer the wrong way here. Are synchronous pvPuts 
necessary to make sure the command has been send to the motor record? 
Should I move the pvPut line to the end of the entry block of state2? 
Are there some best practices how to keep the state machine code clean 
and readable?

Thanks,

Martin

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System