Hello All,

I have a problem with my PLC's. This one PLC shown in the screenshot below freezes up the program.
everything ran fine in 5.4-- now that i have upgraded to 5.5, it freezes up. Nothing else has changed.
As you can see, its a very simple PLC. it just turns the pump on for 40 sec, then off for 15 sec.
everything works fine with the manual button-- it turns the pump on then off no problem.
But if i hit the PLC, it turns the pump on, but never turns off.
In fact, it locks the pump on, even after proview is closed. and the command pwr kill is entered in terminal.
In fact, it will keep the pump running even AFTER the linux box is shut down. Only turning off the power to the arduinos turns off the pump.

Help!!

thanks
bill

some more notes.

It seems like the program is not crashing, but running really slow.
see screenshot.
nothing is yellow or red.

and the manual off/on button turns the arduinos/pump off&on -- no problem.
so the proview to arduinos to pump -- works fine.
and the PLC runs fine when the arduinos are NOT connected (USB connection is unplugged).
only when the PLC is activated with the arduinos hooked up does proview freeze.

Any Ideas? i am stumped.
Everything worked fine in 14.04 and 5.4

Thanks!
bill

Hi Bill,

It could be that the halt cyclesup is detecting a slip and stopping the I/O. See if the IOReadWriteFlag in the IOHandler object is set to 0 when this occurs. If so, also check the DetectCount in the Halt CycleSup object under the PlcThread object. This is set to 1 if a slip is detected.

/Claes