When executing Motion Axis Gearing in CLX, is the servo operating in closed loop?

More specifically, will Position Error Faults still be generated if an abnormal load is present?
My machine has two servo axis being geared electronically to a virtual axis. The programming verifies that all enable relays and brake releasing relays are energized before the MAG instruction executes. Both instructions execute together (parallel output instructions) Sometimes one axis moves and the other one doesn't. The only fault I see is the one hard coded into our fault logic to compare the two axis.actualpositions and trip if they are different by more that 20mm. I'm thinking the external brake could be sticking but I'm not sure if I should be seeing position error or not?

MAG only works on a closed loop servo axis (MSO has executed sucessfully and axis.ServoActStatus is set)

CPU ?
RSlogix Version?
How long has it been working?
Have you replaced or changed something mechanical recently?
Code snippet of the MAG command?
Code snippet of the move command for the virtual axis?

Check the axis.GearingStatus before the master axis moves
It is possible that the MAG is executing with an error that gets overwritten - look at the Motion control.ERR code

Yes, you should get a position error if the servo is trying to move and can't. In the axis properties, you can set the position error limit to be preposterously huge such that it wouldn't error, but I doubt you did that.

I would look very close at the MAG instructions. Just a guess that you did a copy paste error...did you by chance give both MAG instructions the same tagname? Or reference the same axis?

Sorry for the lack of detail. This machine has been running for 5 years no problems.
I have a 1756-L63 CLX5563 Controller Firmware Version 15
Nothing has been replaced recently.
I have 2 identical machines and they both started having the "out of level" faults at the same time. My problem is, the position error tolerance limits are set to 15mm. My hard coded "out of level fault" is set when the two axis are more than 20mm apart. I am getting the "out of level" fault but not the position error. If both axis are geared to the same virtual axis, and both gearing instructions fire together in the program, then doesn't that mean that the position error fault must be overlooked on a slave axis during gearing?

Wow - both machines started the same issue at the same time?. Begs the question "what changed?".

Except when it is off, I believe the servo will throw a position error anytime it is too far from the commanded position. When it is on, I think the servo ALWAYS has a commanded position to compare it's actual position to. I do not believe the servo turns off at anytime during the gearing process. So I tend to think that the servo is not gearing up like you think it is.

Although let me back up and ask - what type of servos are these?

The Trend is your best friend

kekrahulik said:

Wow - both machines started the same issue at the same time?. Begs the question "what changed?".

Click to expand...

+1 - Only things that that I can think of that are common are: Voltage, Product weight change, External Noise.

mamotts

We are trying to determine if your error is at the servo level ( the axis is not following its reference correctly) or in the command (one MAG instruction is not completing before the move)

Fastest way to do this is to use a trend

Note: to get the PositionError to update on the Axis Properties add realtime attribute of Position Error


The above instruction are for a SERCOS servo, if you are using MO2AE then Drive/Motor TAB is Servo and the Torque Command changes to Servo Output Level (+/- 100% = +/- 10 Volts)

You may also try using the following code snippet