Hi dear masters.

I have a problem that I need to use a CD counter which has an output like q0.0 and gets input from an input like I0.0. The PV value is set from Operating panel like MW100. How can I give a number like 1435 or 1400 or etc.? It can only count up to 999 pulses.
Is there any cascade circuit or program to solve it? Really I'm an amateur in it.

Thanks.

 

Hi Morteza.

I am not too sure if I understand correctly, but the way I see it is that you want to load a value of i.e. 1400 into a memory word. Then you have a device that gives out a pulse, and after 1400 pulses, you want an output to be switched? If my understanding is correct, then you can use a Count Down timer (S7-200 counters can take a value of up to 32767), which you pre-load with the value of MW0, and which will count down a value of one each time the input goes high. As soon as the counter value gets to zero, the Counter bit will turn on. In your next segment you can then say: If C1 (Counter 1), then Q0.0. I have added an example.

If this is not what you had in mind, please explain it again.

Rene Venter
Emenem Industrial

 

You can use the IEC counter instead of the standard S7 counter function. Load it from the function block library.

Plug On!
Robert D. Wagner, P.E.

 

You might want to look at SFB0.