What's your max distance to encoder?

[murphy625]

I'd like to hear about your encoder hook-ups.. What is the farthest you have ever successfully run encoder wires?

I am dealing with an application that requires I run 50 feet by way of encoder wire, into a box where it junctions into a flat sheilded festoon cable, another 60 feet from there to another box where it goes back to normal encoder wire again, then 8 more feet to the motor.

Can anyone beat this distance???

Murphy

[lerman]

I assume that you are using a differential encoder. That shouldn't be a problem.

Ken

[Al_The_Man]

I'd like to hear about your encoder hook-ups.. What is the farthest you have ever successfully run encoder wires?
I am dealing with an application that requires I run 50 feet by way of encoder wire,
Can anyone beat this distance???

I seem to remember you saying your application had resolvers on the motors and the encoder was simulated out of the drives?
If that's the case it does'nt count
Al.

[murphy625]

That would be correct AL...

Does it make that much of a difference as far as signal quality goes? I tought resolvers where less prone to noise but not as highly accurate as an encoder.. Am I wrong ??
Also, The question is still valid because I am currently making plans to find a back-up drive/motor combo for my machine and the next time there will be an encoder instead of a resolver.

Thanks !!!

[Al_The_Man]

The resolver is usually less prone to noise because they are very low impedance devices, they are as accurate, but do not have the high resolution that you get with encoders, the method is to often use the resolvers for comutation back to the drive and then square the sine/cosine signals and multiply them electronically to produce a simulated hi-res encoder. As Ken mentioned as long as differentialtype is used and good shielding it should not be a problem, the only other one on long runs is volt drop, so it pays to double up conductors on the +5vdc and common if possible.
Al.

[murphy625]

Thanks !!!!!

Murphy