Encoders and Q

[Paul Ked 0]

Hi. Has anyone used rotary encoders with Q-series? I have one to sense direction and speed - approx 12rpm max - which will require a high speed counter input on one axis and an absolute one to sense angle (8000 pulse/rev) on another axis. I have done this in the past with FX3u using X0/X1 for high speed input and the absolute encoder on profibus. This time I'm using Q (because of MES unit) but I don't know what modules to use. Any ideas? Cheers Paul Ked

[Inntele 60]

Hi, Of course, is possible to use the special module, but I think the best way is to use Profibus-DP, because the same network may used also for pick up signals from/to remote I/O. When to use FX2N-32DP-IF as remote station and discrete and analog modules of FX-series you can save some money.

[Paul Ked 0]

Thanks for reply. I would have gone down the Profibus route but the client doesn't want to do this. I am networking the PLCs/HMI's through E-NET and just had a thought... Is there an encoder with E-Net connectivity? I'll have a look. By the way, what is the module to use for an absolute encoder and would an ordinary input module be fast enough for high speed counters? Cheers Paul Ked

[Inntele 60]

It is not good decision to use E-NET as measuring bus, because that is network of broadband type and it may not guarantee a delivery of measuring results. It's my opinion, but it is not has an alternative to it

[Duffanator 1]

I've used the QD62 high speed counter module before with very much success. I used it on a roll-pack packaging machine and the ring counter function was very usefull for keeping indexing right on. It's made even easier to use with the GX-Configurator (CT I believe....) for that module. Almost no ladder programming to set it up. Maybe that's something you would be interested in.

[Paul Ked 0]

@ Intelle I appreciate your concern, but this application only requires a "tilting" action at very low speeds. The machine is at rest then tilts up 27deg over a period of 30secs then returns to rest. It then repeats this operation (but tilts down) so as long as I see a 'correct' signal every second or so I can cope with the odd 'bad data'. Do you think I would still have a problem? @ Duffenator I'll have a look at that module. Thanks both

[Inntele 60]

The problems with E-NET are possible. I also have similar experience with a low-speed machine and with absolete encoders. But the linear movement of such machine was big. With Q-series I used Profibus-DP, with FX-series - CAN-open. If the time period of signals is two times bigger than scan time you can use standard PLC input. Also in this case you can use inductive sensor (switch) instead of encoder. I did several machine based on this principle... Accuracy is acceptable.

[Crossbow 295]

QD62, QD62D, QD62E depending on the type of encoder being connected. Also, for the Profibus suggestion, the FX2N-232DP-IF is being discontinued this year, so I recommend not following that route.