Siemens S_ODT

[Mike Krell 0]

Can someone explain to me how this On Delay TImer is supposed to function. I am in the process of changing all this over to RS Logix 5000 and I cant really understand what is going on here. I dont get why the TV word is the same as the word that is at the BCD output. Any help would be great. THanks

[JesperMP 2]

Hi Mike. It doesnt look right. The timer will never activate. As you already notice, there something fishy with the MW106 that goes both to the TV and BCD pins. And, variables without symbols are also very suspect. I think the programmer probably meant to use MW106 and MW108 for example, but just never got to test it. Check if T33 is used anywhere in the program.

[Mike Krell 0]

I cannot seem to find T33 used anywhere else in the program, but i see this logic used elsewhere in the program and the done bits are used. Do you think i should just remove the MW___ from the BCD pin? Here is the routine i am working with. http://sites.google.com/site/mkpants/Home/FC5.pdf

[Groo 7]

Noving W#16#1600 into MW106 is moving S5Time value of 60 seconds in 0.1 s increments into the timer preset. After the timer has functiond, then the BCD value is loaded into itself, which would mean it would change and lose the first '1' which would change the timebase from 0.1 to 0.01!! It would also change the value from 600 to whatever the timer value is. I've got something in my mind which tells me that once the timer starts, then the changing the preset time does not change the timer length, could be wrong. So his intention I would imagine was to look at the remaining time. As Jesper says though, it looks all wrong, normal procedure would be to use a different address. Edited 26 Nov 2008 by Groo

[Mike Krell 0]

Is it safe to say then that I can remove the MW__ from the BCD pins of all those timers?

[Groo 7]

Depends on whether he is using the MW's elsewhere, perhaps as comparisons to see what time is left etc..

[Mike Krell 0]

It doesnt seem those MW's are used anywhere but in this routine.

[Moggie 17]

The timer is a "non-retentive" timer. The BCD (Time remaining) time value is being transferred into MW106 so that if the timer stops (for whatever reason) then the remaining time value (if any) is used as the timer preset (TV). Edited 27 Nov 2008 by Moggie

[Mike Krell 0]

I thought that may be the reason, but I wondered why a retentive timer was not used instead. I guess I will just get this programmed as close as i can in Logix 5000. IF theres anyone out there that wants to give me a hand I would love it. Thanks.