encoder monitorig

[bigheadted]

i have a 1024 pulse encoder using channel a and not a feeding into a buffer card which diverts off to find a speed reference for several other machines. this reference is varying too much at the machine end, what is the best way to monitor the encoder pulses, to determine whether it is the buffer box or encoder that is faulty, being that i am sure the reference encoder coupling is ok and that it is being driven at a constant speed. (speed fluctuation is about +/- 10rpm in 1255rpm moving constantly

 

[Barry1961]

I would monitor the input and output of buffer with a 2 channel oscope.

Most of time when a encoder goes bad you can tell by looking at pulse stream.

If it is a noise/wiring problem the oscope will pick it up also.

Barry1961

 

[Skogsgurra]

Tip: Use the pulse-width trigger available on most digital scopes. This is very effective if you are running constant speed. Not so easy when the speed is changing continously.

The pulse width trigger will pick up any glitches and show them. If it doesnt trig, then you can be sure that pulses are OK. (You will have to verify zero, amplitude and 90 degree shift first).

Gunnar Englund

http://www.gke.org

 

[laundry]

Hi bigheadted,
This is quite an easy fault to find, first check your supply to the encoder with a scop pref 20mhz.It must have no spikes or noise on it, Second look at the output pulses these must be perfectly square if you under stand what i mean and have no spikes or ripples any were. check the in put and out put of your buffer look for good clean signals.
There is also one other point,have you ckecked the bearings on your encoder as bearing noise does effect encoder pulses. also what machine is it and do you have any tacos in the same system. As you will know A ataco is a generator look at the output from these if you have them these must have no ripples or spikes othere wise the drive will rampup to match that signal.also check for screen being connected one end only as both ends will cause current loops and induse noise that will cause bad signals

Barry.

 

[itsmoked]

laundry; he got no encoder. He gots a metal to metal proximity sensor do-hicky. That u feed power to and all it puts out is a pulse train, often just a open collector pulse train.

 

[laundry]

itsmoked
What are you talking about he said he as a 1024 pulse encoder do-hicky.

Barry.

 

[itsmoked]

Gads you are correct laundry! Standby while I remove foot from mouth... I confused this post with the "how many pulses can I get ouyt of one tooth counting proximity sensors on my windmachine" post. Now to quietly back out of this post....

 

[Skogsgurra]

I won the bet! Told my friend that Smoked confused the two threads. "How do you know?" he asked. "Well, you know Smoked, I said" So, we are going to have those beers on him now. Thanks Smoked!

Gunnar Englund

http://www.gke.org

 

[itsmoked]

Hahahah, Make the heck sure you toast me for that!

Yeah and wouldn't you know it, the one time I was teasing laundry for a few spelling errors. Twas, karmic it twas.

 

[bigheadted]

thanks anyway lads