On 09/29/2015 10:55 AM, Marius Liebenberg wrote: > Hi All > I have been asked to upgrade a machine that has a very old > control system still running on DOS. It is fitted with > Yaskawa SGDB-03VDY1 drives. I cannot seem to find > reference to that extract number. There are two 2.9Kw > motors and one 0.45Kw. They all have incremental encoders. >> From the documentation that I could find I could not see >> how to drive > these things. It looks like a communications protocol that > they use. I did some work on Servo-Pak drives of about this vintage some time ago. I seem to recall there are two flavors of drives, positioning and velocity. I think they would have model numbers like SGDB-AP for positioning and SGDB-AS (S for speed=velocity) and the AS would take an analog velocity command from -10 V to +10 V. > > I have to decide how to go about retrofitting this > machine. Do I keep the motors (they are still very good) > and keep the drives (dont know how to drive). The Servo-Pak motors (SGDM) have proprietary encoders. A and B tracks are plain quadrature, the C track looks pretty much like A and B, but the phase of the signal shifts to indicate what magnetic quadrant you are in, so that's how they get their absolute commutation. These apparently have magnetic recording on a thin material on a drum in the motor, and if oil or coolant gets into the encoder, it is trashed.
Jon ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
