status bit 40-42

is there a way to use the clock status bits to time functions to happen at a certain time of day or use it with TON or TOF instructions, we are trying to put things such as exhaust fans, water heaters,air compressors, and things of that nature on an slc 501 up to a 504 and use a panelview to manipulate the programming of times to shut off or start up with out maintenance having to come in early to get these things started up and stay late to shut down. this may be impossible i dont know. thanks, david

I'm not familiar with the 501, but a 503,504 or 505 can do what you want.

Just use compares in series, if hour=x, and minute=y, and seconds=z, then (oneshot) do something. You need the one shot, because you will have several scans before the second has changed.

I have used the real time clock to trigger many events in the past.
Just be aware that you may have problems with daylight/standard time changes.


Ken

well actually the hour bit will be enough. i think i know how to use now. never thought of using compare ins. but no more programming than i do i tend to forget a lot. thank you sir

Here's a quick example:
Do not use this exact example, I did a quick cut and paste, and forgot to change the second one shot to another address.


There was a post awhile ago about automatically changing the clock for DST. I don't remember the exact post, but a forum search should find it.

This is a program I did recently using a Micrologix 1200 with a PV 300 Micro to set the time/days to turn on a chiller. The Panelbuilder file is the second file. The files are not zipped, just change the zip to rss for the RSLogix file and pba for the Panelbuilder file.

I will state that the program is an example,.I do not claim it to be good programming but will give you an idea of "HOW TO". The ML has a clock/memory module that is addressed different than SLC, some SLC's use status bits for time/date.

NOTE: Panelviews have an internal clock too which can be used. Look at chapter 3 page 32 of this manual: http://www.ab.com/manuals/eoi/pdf/2711-um014d-en-p.pdf

The RSLogix file is attached, just rename to superseal.rss

This is the Panelbuilder file for the PV 300 Micro, just rename it to superseal.pba

I did not use a one shot, I maintained the start bit for 5 seconds and latched it. I never got the chance to clean the code, it worked and they wouldnt let me make any changes.

thanks guys i am trying all these to see which i can use. i am not the best with panelviews so i may be a little while figuring that part out. thanks, david