Hi, all;
This previously was stuck on the tail end of an older question I asked, so I want to separate it out in another thread in the hope that someone can give me a hand. Background first:
I'm trying to bench test some aerotech ba20-320 drives. These are old school analog servo drives that take +/-10V input and can run brushless or brushed servos. Amps are 20 peak, volts up to 320. I have the drive connected to a compatible servo on my bench. I also have the following connected:
* Tachometer to the tach inputs on the drive
* Drive enable (limit switches are inverted by jumpers for now)
* 9v battery/potentiometer to command input, other end of differential input tied to GND per manual
* Servo power wires to A and C terminals (A and C are used for brushed drives and B is open)
I've set all the jumpers in the drive to the "brushed" setting. Additionally I've set jumpers to enable tach feedback (as opposed to encoder). I've set the DIP switches for the drive to allow full current and full peak current. The drive can handle up to 20 amps peak for 2 seconds, and continuous is 10 amps. The servo is larger than this, it can handle up to 21 max amps (it's a SEM MT30). However, I have a 10 amp fuse inline with live power which comes off the inside of a 240->110 step down transformer (this drive can be line powered per the manual, but I wanted isolation). DIP switches are also set to velocity mode. I've tried both supplying a command signal with a 9V battery and also the drive's internal "test" mode.
After all that, I can't get any servo movement. I do hear harmonics a bit when the drive is enabled, but no power is output to the drive.
So my question is, what is a normal bench test config for an analog servo drive? If you've tested a drive this way, could you please let me know what sort of connections usually have to be made - power, servo, tach, limits, etc? If a connection says it's "active low" vs. "active high" then it should be active when grounded (to the drive's common ground) right? Do you just connect wires to the drives one-off, or do you have a "test rig" you use?
I'm tearing my hair out trying to figure out what these drives want in order to operate.
Thanks,
Erik