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Guli

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Posts posted by Guli

  1. 1 hour ago, Ausman said:

    100mS = 0.1 Seconds, so the really critical thing here is what is the off time.  Are you saying the pulse is 100mS with 50 ON and 50 OFF?  Or the pulse itself is 100mS ON.  In that case what is the shortest time it will be OFF?  If, for instance, the OFF time is 50mS then the plc can easily read this change of state situation on a normal Input.  Scan time on a simple program is measured in mS well below 10, often 1 or 2.  So you have a relatively long time for the change of state to be accurately read.  But that is why the question about OFF time.  If it is only a few mS, which I doubt, then you will need to use a high speed input, but even an OFF time of 10mS should likely be read OK.

    If your program is simple and the OFF time is >10 like I have written about, and your plc is not reading the input change correctly, then you have something wrong in your wiring or your other input related interfaces. 

    Your question about writing 1 to MB shows a need to have a good look at the help files about the various operands used in Unitronics, and how they are implemented in the ladder. 

    cheers, Aus

    100mS is the ON pulse duration. The device is a Power meter that pulses every 1W/h.

    The max. load on the Power meter is about 8kW. So on max load it pulses with 2,22 Hz. 

    I found out, that time to time a pulse is read by PLC.

    That means, the scan time is too slow to read my pulse.

    OK, back to my question, is there any sample or can anyone write me one, how to read pulse with High Speed Input.

     

    Thank you!

  2. 49 minutes ago, viscoelastic said:

    For that short of a dwell time; I would use a high speed input. Even if the standard input could read it, you may have missed counts because it relies on checking each scan of the program. High speed inputs are independent of the scan.

    You see opposed of using a high speed input. May I ask why?

    Hi,

     

    is there any sample how to properly program a high speed input so it writes  1 to MB on rising edge of pulse?

     

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