Re: [CAD_CAM_EDM_DRO] AC Servo's

Roy J. Tellason wrote:

>On Friday 12 August 2005 11:32 pm, Jon Elson wrote:
>
>
>>>I'd probably prefer a digital setup, but fear I may have to change both
>>>motors and drives?
>>>
>>>
>>Yes, keeping the drives is the best option, if possible. Some drives can
>>accomodate a variety of motors, others are strictly proprietary. You need
>>to check if the encoder has standard commutation outputs, or if the motor
>>provides these (the typical Hall A,B C outputs.) Yaskawa servo pack
>>drives use a proprietary scheme where the "Z" channel of the encoder has
>>a phase relationship to the A and B encoder tracks that gives the drive
>>the index position as well as the commutation info. So, both the drives
>>and the motors are totally proprietary, and can't be used with anything
>>else. A number of other makers have similar schemes.
>>
>>
>
>Are you saying here that the encoders are also likely to be proprietary in
>some way? Not exactly real high up on my list, I have a couple of units in
>my box of motors that have encoders mounted on them, and you've got me
>wondering...
>
>

I can guarantee that Yaskawa servo-pack motors have a very proprietary
encoder.
The A and B signals are normal, but the Z signal looks very much like
the A or
B track, except that it flips the phase relationship, I think, 6 times
per revolution.
There is no A, B C (or U,V, W) commutation signal provided.

I think a number of makers have schemes similar to this on their motor/drive
packages.

Jon