High speed counter

[Guest srossi]

Has anyone used a IC693APU300 High speed counter module on a 90/30. I am using an AB phase encoder and would like to know how to set it up and also how to reset it. I have used an example program supplied by the distributor butthis does not work (eratic counting). I have checked the encoder with another PLC (mitsubishi)and it works fine. Thanks S Rossi

[Steve Bailey]

I've done plenty of work with the 90-30 HSC. I even have one available to practice on. Olease define 'erratic counting'. Post your wiring, the configuration details of the HSC module and the ladder logic you're questioning and I'll try to help you get it straightened out.

[Guest srossi]

Thanks for the reply Steve. Erratic counting as follows. As the encoder moves from one position to another, an error of one count is noticed when compared to the mitsubishi. This shift of one count then accumulates as we move from point to point and back. The shift can be positive or negative. The mitsubishi is always correct and is simply wired in parrallel with the GE. Count frquency is only 20 Hz. We have noticed that as we "rock" the encoder about a transition of one of the inputs, we can get the count shift, but the mitsubishi is always correct. We have tried a second HSC card but have the same problem. Thank and regards Sam

[Steve Bailey]

Please post the configuration data for the HSC module. Is it set up as Type A, Type B, or Type C? Quadrature encoder or Pulse/Direction? Are you using ladder logic to reset or enable counting? Are you using any of the hard wired signals to control the counter? Let me make sure that I understand your test setup. You have an encoder connected simultaneously to the GE Fanuc module and the Mitsubishi. Both units start with the same accumulated count. You rotate the encoder by some amount and then reverse it back to the starting point. When you get back to the starting point you find that the Mitsubishi's accumulated count is back to its original value, but the GE Fanuc's is one count higher than it was originally. If you repeat the test, the GE Fanuc's accumulated count will gain one count on the Mitsubishi for each cycle. If you change the amount of rotation do you get a larger difference? Does the discrepancy show up after the first direction reversal?, after each direction reversal?, only on reversal from CW to CCW (or CCW to CW)? Are you looking at accumulated count values or is there any scaling being done in ladder logic? Why are you convinced that the Mitsubishi's value is correct and the GE Fanuc's value is the incorrect one? It looks like our schedules are such that we are only going to get one exchange per day. Given that, please provide as much information about your system as possible. Otherwise, this could drag on for days. If you find yourself in a position where you have some time to experiment with the system, contact me through this forum and we can work out how to communicate in real time.