CQM1 CPU44 Counter errors

[garywalsh 0]

Hi... I am adding a couple of counters to monitor some inputs, when i download the program to the plc and then put in run and monitor the counters dont decrement, the PV just jumps around. I am using 253.15 to reset the counters and this seems to not work either as the PV does not set to the SV. The counters i have added are below. LD HR28.01 LD 253.15 CNT 001 #3000 LD 002.07 LD 253.15 CNT 002 #3000 Any ideas?? Gary.

[Sleepy Wombat 27]

Check to see if you have timers allocated the same number ie do you have a timer 001 and timer 002 this is becasue the timers and counters in the older models of PLC shared the same data area.... I use to program the timers numbers counting up and the counters counting down from the max... never the twain shall meet... ie T000, T001, T002 C511, C510, C509.... don;t quote me on the valid timer and counter numbers though....can;t remember and can;t be bothered to look them up again... OR simply start counters at C200 and up and timers from T000 - T199

[garywalsh 0]

Thanks, i will check it out and get back to you.

[garywalsh 0]

Thanks sleepy, that was it...I never realised that, handy piece of info thanks....

[Guest anonymous]

Hello Gary, This (as Sleepy says) is only for the 'older' PLCs (CPM, CQM, C200HE / G / X, SRM etc). If you find yourself invoved with any of the later devices, then the CS / CJ / CP ranges have individual T and C areas, and the numbers can be shared, i.e T0 - 4095 and C0 - 4095. (total of 8190 timers and counters!). Hope this helps.