Real Time Clock In ladder logic

[dr00cm]

I believe I am needing to create a real time clock in ladder logic as the 1400 I am working with doesn't have one.
I will have to bring the time to the panel view and have the user input the time from the panelview (if its considerably off or by power outage reset).

I need bits to turn on/off fans on specified times

Anyone have an example of something like this that I could use as skeleton/guide rather than starting from scratch?

The Plc is micrologix 1400, 1766-132bwaa
Panelview Component 600, 2711C-T6C


I've checked the system files 'S' and there's no clock. Just the free running clock S:4. So I thought that I could start a series of timers/counters which will drop min/hour/day/month each in F: registers for use to the hmi.
Drop/move numbers in into other registers from a sceen/user input to set the time.

Take counters to set the on/off time, and place bits appropriately to control the fans.

So I'm not sure whether to a) make the clock in logic, b) use free running clock somehow, or, c) how to bring the time from the PV Component 600 to use?

 

[sthompson]

Welcome to the Forum!

I haven't used an ML1400, but I believe they have an RTC. Have a look under the Function Files in the Controller Section, then Click on RTC.

Stu....

 

[krakenfan69]

http://www.plctalk.net/qanda/showthread.php?t=75459

Kraken Fan #69

 

[dr00cm]

I reviewed this thread (from Kraken Fan #69) and checked in the Function Files for the RTC, and it seems there is RTC:0 with yr, mon, day, hr, min, sec. I'm off away from the processor and not sure just how to use/access these in a ladder, (RTC:0.HR, Integer) and if they will actually work when im online.

I did program the system a few years ago but still somewhat of a novice with programming.

Thanks for the info.

I need a way to try this and test a program offline and i still may have to build a timing ladder that at least counts hours in case i cant get the RTC:0 working.

Any further comments are appreciated, thanks

 

[sthompson]

Unfortunately, your probably not going to be able to test it without a live PLC in Run Mode. You could set it up something like this.

Stu....

 

[dr00cm]

ok, yes, that makes sense, I'll try that.

thanks