Encoder specs

[OCNC]

I have a Yaskawa Servo type T03L-DP11 rated at DC 22.5V, 4.5A P#801977-001. The encoder has an inner and an outer reticle. I've attached photos. I'm looking for some information on the purpose of the double reticles and how I can determine their resolution. Also does my tentative labeling of the encoder wires seem plausable? Any input is appreciated.

Thanks.

Chris

[Al_The_Man]

What type of motor is it? AC, DC brushless or DC brushed? The low res track could be commutation tracks if it is DC brushless, this takes the place of the older hall effect transistors. The connections are probabally correct for the +5 and common, and signal look ok,that would mean there is no marker pulse though. The resolution is often engraved on the glass disc near the boss.
Al

[ViperTX]

I believe they have the same number of divisions (lines, reticles,etc.) they are out of phase, this gives you 2 signals where you can tell if you're going clockwise or counter clockwise. I guess you could try and count them ......or turn the motor x number of times count the transitions on one signal and divide by x.

[OCNC]

Originally Posted by Al_The_Man What type of motor is it? ... Al

It's DC but I'm not sure as to how to identify it as brush or brushless. It has two power leads marked A and B. There are no obvious brush holders visible from the outside of the housing. When rotating the shaft by hand it gives a slight detent type of resistance similar to but not as strong as a stepper motor.

Another photo of the reticles is attached. I don't find any markings on the disk. This photo clearly shows an indexing line that I hadn't noticed before.

Chris

[ViperTX]

That extra mark is an index mark and is generally used to determine the speed / rpm.

[Al_The_Man]

I have never seen one with two reticle tracks, as the usual quadrature out only need one track as the heads are spaced to give a 90deg phase shift. The marker is used for reference or home position, after seeing a home limit switch.
The second (inner band) is too fine for commutation. anyway you would have three motor leads if it was brushless.
Al

[ViperTX]

http://www.yaskawa.com/site/Support....rvoMotors.html

It looks like the index is definitely a speed (rpm) indicator.....anyway...good luck

[Al_The_Man]

Originally Posted by ViperTX http://www.yaskawa.com/site/Support....rvoMotors.html It looks like the index is definitely a speed (rpm) indicator.....anyway...good luck

I see the information on the motor but not the bit about using the marker as a speed feedback, I do see the encoder sheet that shows the marker as home pulse, the only other thing I have seen the marker used for is a used as count verification of the pulses per rev, in case of missing encoder pulses,
If the marker was used as a tachometer, it would be virtually useless at low rpm.
I would hazard a guess that if there is reading heads above the inner track, that could be for digital tachometer, and it is possible the A & B channel are used only and although the disk has a marker pulse it may be just that they used a standard disk but it is not wired to take advantage of it.
Al

[ViperTX]

Yep, the specs were incomplete...yet we've strayed from the problem...how does OCNC use these encoders......I would suggest power up the motor and the encoder....and look at the output with a dual trace oscilloscope to determine if it's a quadature output or ??? when the motor is running at a particular rpm.

[OCNC]

Thanks for all of the comments. I hooked the encoder to a 5V supply and using a couple of 5V LEDs determined that both reticles exhibit quadrature. So it would appear that two resolutions are available. (The index seems to be unused as Al suggested.) Knowing this I should be able to hook the servo up to a driver in the usual configuration.

Chris

[GTAYLOR]

Chip Sweeper:

Can you share any data sheets you have on the Yaskawa T03l-DP11?

Thanks,

Gtaylor