View Full Version : Newbee's question
November 8th, 2005, 09:05 AM
Iím new to: PLCS and to RSLogix. Iím attempting to learn on am obsolete SLC500, my problem is finding a way to setup a timer to count 15 minutes easily. I realize that this controller is limited to 10 milliseconds and -/+ 32,xxx counts. Looking for a suggestion.
November 8th, 2005, 09:20 AM
It is called cascading timers. Done bit on first on, starts the second one and so on and so forth!
November 8th, 2005, 09:21 AM
There's a clue in the question; "timer to count". You set a timer to time for a given period and then reset itself, you set a counter to count the timer's DN bit (ie. the number of elapsed periods) and set it's own DN bit after the number of these periods that make 15 minutes.
November 8th, 2005, 09:29 AM
You probably have an old fixed SLC 5/01.
If you had a Newer SLC you could set up a timer for 1 Second with a preset of 900.
But you don't have that option. ( I presume)
One option is... you can set a timer with a preset of 100, and when it is done, add 1 to a counter and reset your timer.
Now when the counter reaches 900... do your logic, and reset the counter.
Why not try this on the new simulator (http://www.plcsimulator.net/)?
November 8th, 2005, 09:42 AM
Thanks, when you get as old a me, sometimes the mind goes on a holiday. I will set up the timer routine and see if I can get it to work. I know it will if I get it right.Thanks again to all of you for responding so quick and kindly. Butch