Host Engineering Forum

General Category => General Discussion => Topic started by: Stan on February 15, 2013, 08:51:44 PM

Title: Odd timer behavior with DL 260 PLC
Post by: Stan on February 15, 2013, 08:51:44 PM

I am having a problem with timers in a DL260 PLC.  The timer completed bits on several of my timer status bits are randomly turning on and off. This happens while the timer is still timing out and it happens even after the timer has timed out.  It's as if some other logic is overriding the timer status bits but I cannot find anything obvious in my program where this might be happening.  I've programmed many DL205 series PLCs and this is the first time that I've seen this behavior.  Any idea as to what is going on?

Title: Re: Odd timer behavior with DL 260 PLC
Post by: b_carlton on February 15, 2013, 08:55:57 PM

Can you post a section of the program with the timer? The whole program would be even better. Are there any external devices (HMI, network) which are writing to the same area as the time 'done' bits?

Title: Re: Odd timer behavior with DL 260 PLC
Post by: Stan on February 16, 2013, 08:44:03 AM

I've attached a zip file with the complete program.  I am using a PC running LabVIEW as the HMI but the timers act the same whether the HMI is running or not running so I don't think that the HMI is causing the problem.  Thanks for looking at this for me. I appreciate the help.