View Full Version : Need Help! Spindle encoder - how many lines?

03-25-2011, 06:05 PM
I have a J325 with a General Numerics spindle motor and I am trying to get get it hooked up for closed loop vector mode. One piece of info I can't find is how many lines the encoder has.
Here is the basic info I know;
FANUC- General Numeric Motor

2.2 KW continuous 3.7KW 15 minutes

11amp Continuous 15 amp - 15 minutes

1500-8000 RPM

3 phase

4 pole

Volts 200

Type A06B-1002-B600 #2000

03-25-2011, 06:37 PM
If setting up for vector control, then the encoder should be on the motor, as opposed to the spindle encoder which is fitted on the final spindle shaft.
Is there a number on the encoder?
Most were 1024p/rev.

03-25-2011, 08:26 PM
I haven't dug into the motor to see the encoder - don't really want to - but it is in the motor. The cover on the box where the terminations are has a wiring chart. The connections are A, A bar, B, B bar, 5v, 0v, a shield, thermal 1 and thermal 2.
I am using a Unidrive classic for the spindle drive. I am trying to get from Open loop to close loop vector control. I am at a point where I apparently need to do some trouble shooting. I have never used the encoder so I am not even sure it works properly. I'd guess I might be able to see some voltage across a-a bar and b-b bar and possibly a change if the motor was turned. I only have a volt meter.
I have made changes on the drive from OL to CL but now the spindle doesn't spin. It worked during an autotune, so I put the belt back on, but now I can't get it to spin...my control is via Mach 3.

Before I go swapping the encoder connections I would like to get a better idea of what is wrong...its possible I have some problem with parameters. Although making sure my encoder has power would be a good starting point but any and all advice would be welcome.

04-16-2011, 09:53 PM
I have a Manuel that you can have for the S&H

08-11-2011, 07:39 PM
I am finally getting back to closing the loop on the spindle...I really need the torque...
I need some trouble shooting advice because it seems I have an encoder "problem" My spindle seems "unstable" - its pulsing back and forth when it should be stopped. The CT Emerson spindle driver has a monitor to watch the encoder count and it seems to increment ok but not decrement, it also does not seem to produce 4000 counts in a 1/4 turn - its more like 500. I will have to recheck the wires coming from the encoder on this FANUC motor in a J325 but I have PA -RA - PB - RB 5V gnd and OH1 and OH2 listed on the motor plate. The wires unfortunately change color when they leave to box so I have had to ohm them out to determine which is which. What I am hoping is that someone has an "AH-HA" moment and can suggest that the symptoms are indicative of a mis-wire, or broken connection or...?



08-11-2011, 08:07 PM
Try swapping the encoder phasing/direction, swap PA & RA.

08-11-2011, 10:19 PM
That change PA to RA, reversed the increment direction from CW to CCW...I still need to find a way to figure out if the encoder is working properly... I don't seem to get the correct number of pulses in a 1/4 turn (500 vs 4000 is expected) I've changed the parameter for the number of lines from 1024 to 512 to 256 ...but can't go any lower...and it seems I should be at 128 to get 4000...This CT Emerson has way too many things to change...maybe I'm missing something


08-14-2011, 11:02 AM
I am starting to think that the PPM of the encoder in the General Numerics motor is 128, which is too low for the CT Emerson drive to work with. Does anybody know that it has a higher PPM?
My next step would be to take a look at the encoder. Any advice about getting to it and removing it? Any suggestions for a replacement?