adccommunitymod (AutomationDirect) asked a question.
EDRUM question (but applicable to DRUM as well)
Created Date: November 19,2013
Created By: Biederboat
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Dang I have fallen in love with EDRUM. One little thing I'd like to be able to do though is use a V-memory location for the "count " field (so I can change the time on an HMI or have recipes) but that does not appear to work. Is there another way to achieve this? The only way I can figure out is to use the Event field when a timer is complete (where the preset is loaded via V-memory). Thanks, BB
Created Date: November 19,2013
Created by: bcarlton
The 'count ' field is part of the hard instruction - kind of like a 'K ' constant (if used) is part of a LD instruction. But it doesn't have the 'V ' memory option.
If you REALLY need to have variable timings then you might consider abandoning the EDRUM (I know, it's so nice and compact) and go to Stage programming. Each Stage is essentially one step but you can have a LOT. And each one can be individually configurable on how it transitions to the next Stage. The added flexability may compensate for your 'lost love '.
Created Date: November 19,2013
Created by: Biederboat
Thanks BC, likely while you were typing I was searching and found another post (and hey, you answered that one!) that mostly answered it in the way I was thinking: http://forum.automationdirect.com/showthread.php?t=11625&highlight=DRUM
I'm currently working on this (I only need two variable timers out of about 10 steps so it's really pretty simple) but I'm struggling to figure out the input part (e.g. current step = "X "). Can you point me in the right direction there?
Much appreciated!
BB
Created Date: November 19,2013
Created by: bcarlton
In the DRUM you showed you had CT0 as the first counter. Looking at the documentation that means that CT3 would be the 'Current Step ' counter. So a comparison rung would be:
CTA3 = Kxxxx (eg CTA3 = K4 means it's on step 4) then do Timer. If you have a seperate condition which must be true also just place that contact on the rung before the timer.
In the DRUM use that timer 'done ' bit as the 'Event '. Set 'counts ' to K0 for that step.
(And the post you linked to diescribes this for the Click PLC but it's the same reasoning anyway.)
Created Date: November 19,2013
Created by: Biederboat
Got it, and working, thanks!
Created Date: November 19,2013
Created by: Biederboat
Dang I have fallen in love with EDRUM. One little thing I'd like to be able to do though is use a V-memory location for the "count " field (so I can change the time on an HMI or have recipes) but that does not appear to work. Is there another way to achieve this? The only way I can figure out is to use the Event field when a timer is complete (where the preset is loaded via V-memory).
Thanks,
BB