Tia portal ctu

One more interpretation of @Puddle's idea: if we leave ctu1.QU on the R pin of ctu1, as when we started, then that will drive the bit ctu1.R, which becomes 1 for a single scan cycle at each first stage (ctu1) reset, and so could be used as the trigger for the cascaded secondary ctu1. This works, and might be the most easily understood six months from now:
two_ctus_puddle_05.png
 
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Sorry for not taking the time to post a screenshot of my approach. I've just gone to do it and realised that how I wrote it doesn't actually work!

I've attached a screenshot, but where I've used M10.0 to trigger the reset I originally intended to directly use CTU1.R. It seems there must be a tag assigned to the input at R and it won't work if it's just used in an assignment elsewhere in the program.

I like this more though:

Cascade counter.png
 
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This maybe a hangover from the days of me programming S7-200, but I was sure that if you just connect the 1 second contact to a counter that it counts for each PLC cycle whilst the contact is closed. That is why I added a Rising Edge after the 1 second pulse contact. I have a system on the test bench, I guess I could have tested it before posting, but I like to live on the edge.

The second oneshot is superfluous
In my life you can never have too many superfluous oneshot contacts :)




Just tested it, and it is a hangover in my programming from the S7-200, I have been wasting oneshots for years :-(
 
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TI was sure that if you just connect the 1 second contact to a counter that it counts for each PLC cycle whilst the contact is closed.

I'm sure I've had the same issue the first time I used a counter on TIA V15 using an S7-1200.
I was very new to it though, so it's more likely that it was my fault as absolutely nothing worked as intended with that first batch of code.
 
May u help me solve the over level by using logic ladder language?
Welcome to the forum!

Please start a new thread, and supply more information:

  • what inputs affect the running of pumps 1 and 2?
  • do pumps 1 and 2 always run together?
  • if pump 2 is not running, what is the list all events (combinations of inputs*) that should cause it to start?
  • if pump 2 is already running, what is the list of all events (combinations of inputs*) that should cause it to stop?
  • * events =combinations of inputs (start3/stop3/level/pump2):
    • start3=0/stop3=0/level=0/pump2=0
    • 0/0/0/1
    • 0/0/1/0
    • 0/0/1/1
    • 0/1/0/0
    • 0/1/0/1
    • 0/1/1/0
    • 0/1/1/1
    • 1/0/0/0
    • 1/0/0/1
    • 1/0/1/0
    • 1/0/1/1
    • 1/1/0/0
    • 1/1/0/1
    • 1/1/1/0
    • 1/1/1/1
 

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