Timer that self starts...an RSlogix boot loop??

[spence144db]

I am hear to call upon the vast knowledge of the community.

If you look at the program below you will see a sequence of timers that should all run and at the end of the sequence they SHOULD just stop. (I think) when the last timer in the line up is done the T4:1.TT in LAD2 R:0 will just activate itself with no human input??!!!?!? Can some one explain to me how this is possible.

Also if you look in LAD 3 I am in the process of trying to figure out how to make this whole process run 1 time with a switch off and run 2 times then stop with a switch on...i have been looking at this problem for about a day and my head hurts.

 

[chavak]

The timer is not running by itself, your input I:1.0/11 is "forced on" in the data table.

The Status do not turn green when you go online for forces, it turns green only when the physical input is on. But you can see a word "ON" on the rungs where ever it is addressed

Regards
_______

 

[Lancie1]

If you look at the program below you will see a sequence of timers that should all run and at the end of the sequence they SHOULD just stop. (I think) when the last timer in the line up is done the T4:1.TT in LAD2 R:0 will just activate itself with no human input??!!!?!? Can some one explain to me how this is possible.

Spence,
Timer T4:1 in Lad 2 Rung 0 will work like this: If the FORCE is removed from I:1/11 (as it should be for normal operation) then if the Pushbutton is a momentary-contact button, then T4:1 will start and be held in by XIC T4:1/TT for 5 seconds, then stop and do nothing else until the Cycle Start PB is pressed again. On the other hand, if the PB is a maintained-contact button, then the timer will still run one time, but will be unable to run again until the PB is turned off.

If you want to make T4:1 "just activate itself with no human input" (a truly "self-resetting" repeat-cycle timer), then add a XIO T4:1/DN on a parallel branch with the I:1/1 Pushbutton. The pushbutton will not be needed then (you can delete it and its rung branch).

I am in the process of trying to figure out how to make this whole process run 1 time with a switch off, or then run 2 times then stop with a switch on...

If you can make a list of the process steps as shown below, then I will be glad to fix your program to do the job:

1. Stage 1 starts when xxx happens, and ends when xxx. During Stage 1, these things should happen: xxx
2. Stage 2 starts when xxx happens, and ends when xxx. During Stage 2, these things should happen: xxx
3. Stage 3 starts when xxx, and ends when xxx. During Stage 3, these things should happen: xxx

In other words, please describe the process operation (not your program). Then I can help you to fix your program to work correctly. The reason is that it appears that you may be making some wrong assumptions. You may be trying to use only the timers to control your process, when you really should be using feedback signals from the process (limit switches) where possible.