Centroid Community CNC Support Forum

I am an employee of NIAR at Wichita State University. We're attempting to implement a gantry control system using Centroid's Oak board and motors and drivers from Mitsubishi.
We've contacted Centroid for support a few times, but after still having issues it's time we created a full detailed forum post

Link to photo album of Setup Photos

There is a lot of stuff here leftover from a previous setup that, to my knowledge, we are no longer using anymore. Apologies for any confusion.
(I took the photos myself, but I'm the person in charge of software rather than the wiring so I might be missing important information in the photos)


We've followed the steps in the Oak install manual, but we've come to a problem when we're trying to jog the machine. I can open the MDI panel without issue, but when we try and jog the machine we get a 410 X axis(1) position error. (Not connected at the moment, but when we setup the Y motors we were getting a y axis error as well)

When attempting jogging, the PID menu displays numbers increasing in the correct directions (+/-)
When we physically move the machine the position in the software updates, so at least there is a connection somewhere. I pushed the system until the motor moved ~1 rotation and the output of the position was 8198 when we should be expecting ~32768.

Link to photo album of Software Screenshots


We thought the issue might have been a lack of an installed Emergency Stop, because I had the EmergencyStopOK trigger overridden and the drivers are displaying "AL E6". (Which appears to correspond to an Emergency Stop flag) However with the EStopOK overriden in CNC12 and a faked current input simulating the EStop for the motor drivers, we still got the same position error when we tried to jog. (This could still be an issue and we will install an EStop button eventually, but it appears this is not the only issue we're having)

We have tried several ideas, but without any success and are unsure on where to proceed from here. We would appreciate any assistance in the matter.

Any pictures of the encoders themselves, or a manual for them? Why do you think you should have 32768 counts per rev? Based on your observation of 8198 counts when you moved it one turn, it would appear that you have 2048 line encoders and therefore 8096 counts per rev. Change your counts per rev in the motor parameters screen and see what happens.

What do you have parameter #27 in the servo amplifier set to? On page 5-15 of the manual it states the default is 4000 which means that the corresponding Centroid motor parameter encoder counts per rev should be set to 16000. Counts per rev in a quadrature system are 4 times the number of pulses (lines).

Are you trying to run the servo drives in analog velocity mode? If so, you will need some non-zero PID gains.

Are you trying to run the servo drives in pulse-train position mode? If so, you should set Parameter 256 = 2.

Can you make the servo move back and forth a small distance, repeatedly, without "410 ... position error" stalls, if you use Incremental, Slow, x100 jog mode? If so, and you are running in pulse-train position mode, then you have a mismatch in either the input multiplier or the encoder output ratio. To work in position mode, you have to configure your drives so that when Centroid clocks out N pulses of movement request, the resulting movement is N encoder counts (which, as Tom points out above, would be N/4 encoder "cycles" or "lines").

But now that I look at the "OakMitsubishiConnection.pdf" file, I see that the position-mode request wires are not connected. So you must be in analog velocity mode. You need non-zero PID gains if you want to see movement.

To get started, try something in the neighborhood of Kp = 0.04, Ki = 0.001, Kd = 0.08, and Kv1 = 80.

Thanks for the help, I wasn't expecting a response so soon
I have put a better picture of the encoder connected to the motor on the photos page, it has a red light on it's "encoder" value which supposedly indicates an encoder error. We are looking into the details of the encoder, but nothing to report at the moment.

tblough wrote: ↑Thu Aug 20, 2020 7:54 pm Any pictures of the encoders themselves, or a manual for them? Why do you think you should have 32768 counts per rev? Based on your observation of 8198 counts when you moved it one turn, it would appear that you have 2048 line encoders and therefore 8096 counts per rev. Change your counts per rev in the motor parameters screen and see what happens.

We thought we should have 32768 because that is what the default was set to, also when we asked Centroid support one of the replies was "From the PID menu, with Estop, When you turn the motor shaft one turn, you should see the encoder count 32768 counts. Is this happening?" We changed the encoder counts/rev in the motor menu to 8192 and 16000, but saw no changes to jogging. This will probably be correct for the future though.

cncsnw wrote: ↑Thu Aug 20, 2020 9:01 pm Are you trying to run the servo drives in analog velocity mode? If so, you will need some non-zero PID gains.

But now that I look at the "OakMitsubishiConnection.pdf" file, I see that the position-mode request wires are not connected. So you must be in analog velocity mode. You need non-zero PID gains if you want to see movement.

To get started, try something in the neighborhood of Kp = 0.04, Ki = 0.001, Kd = 0.08, and Kv1 = 80.

We changed param 256 to 1, from 0, so it is now in velocity mode. We also set the PID values as recommended. Now when we jog there is a colored bar at the top of the screen under the X position (Power I assume) and we are also now getting a PID Out value when we jog. When we jog with incremental jogging disabled we still get the X axis Position error; However when we jog with incremental jogging enabled we are now getting a Full Power Without Motion Error.
We've looked at the limit switches and don't believe there to be an issue with them, nor can we see any physical stops.