Help with IDEC Microsmart

[Stig]

I'm trying to program an IDEC Microsmart series PLC. The WindLDR program does not have a built in retentive timer. I am trying to create a cook program where a preset timer start counting down after the required temperature has been reached, but if the temperature falls below that value the timer pauses until the value is reached again. After it has timed out it would move to the next stage in the cook cycle. Can any of you put that into a ladder logic form? I have been trying, but my apprenticeship hasn't gotten me into ladder logic yet, so I am pretty green at it. Thanks!

 

[Lare]

one second pulse, integer and add or sub instruction?

 

[Stig]

1 second pulse, 120 minute cook cycle, subtract instruction.

 

[Lare]

so maybe something like this on ladder logic...

 

[Stig]

That just might work, I will have to run it later tonight if I get the time at work. Thank you.

 

[Lare]

You are Welcome

This is just example how retentive timer can be done on ladder

If you want use add insruction, you only need change locig little bit.



by the way, if you use integer variable, this timer is limited to 32767 second / 9 hours (or 65535 if you use Unsigned integer)

But if you use double integer, then I think that you have more than enought time on your timer (max 2147483647 seconds or 4294967294 demending is variable signed or unsigned)