Centroid Community CNC Support Forum

Those drawings were specifically labeled "ACORN_to_GSK980MDa_Connector" because they show connections to the control end of the existing cables not the drive end.

The difference in wiring is because the DB25 outputs are logic outputs that switch between +5VDC and 0V. The screw terminals are open collector (sinking) outputs that switch between open circuit and 0V.

Ah, I think I understand now, the drawings show the existing 980MDa connections to the DA98B AC servo driver, as opposed to the Acorn connections to the same thing?
When I was a photocopier technician back in the 1980s, we used to refer to a 5v signal as being "high", a 0v connection as "low" and a 3rd state as not connected (N/C). The DB25 Acorn connections switch between high and low, whereas the Acorn screw terminals switch between low and N/C?

I made a new cable today based on ACORN_to_GSK980MDa_Connector-R2.pdf that you posted Centroid_Tech2. Sadly it doesn't work. The servo fails to turn and although the driver locks the motor in position as soon as I power up the Acorn, there is no further movement, when, for example I jog the axis. The cable that I made based on your previous wiring diagram still works, even though the Acorn wizard shows the output is "screw terminals".
I wonder if I have misinterpreted your diagram? I would be really grateful if you could look at the attachment that details my cable and which wires connect where.

fyi...both the db25 and the screw terminal output step and direction at same time.
the selection in the wizard is to get the direction set correctly since there is a cw/ccw flip between db25 and screw terminals.
im sure chuck will give you some more advice, in meantime to help us help you better, please start an online photo album and populate it with lots of photos/videos/diagrams etc..
info on how to do this with video etc. is here.
https://centroidcncforum.com/viewtopic.php?f=60&t=1043

Thanks for that snippet of info Keith. So based on what you are saying, you could expect a reversal in direction of the motor between screw terminals and DB25, even though no settings were changed?

I would still be grateful for Chuck to look at the connection info that I posted.
"I would be really grateful if you could look at the attachment that details my cable and which wires connect where."

After more thought about this setup, I think it really makes no difference whether I use the DB25 connector, or the screw connectors for the servo drive connections. I have a working DB25 connection for one axis, so I will make the requisite number of extra cables for the other servo controllers, using the DB25 connector, wired internally to my external ports and move on.
That is unless you see any problems with this approach?

dmbgo wrote: ↑Thu Jun 01, 2023 6:27 pm Thanks for that snippet of info Keith. So based on what you are saying, you could expect a reversal in direction of the motor between screw terminals and DB25, even though no settings were changed?

that is correct.

Today, I started to make the final drive setup for the controller, using the onboard Acorn DB25 connector. I made a break out cable from the DB25 port on the Acorn board, and configured it as previously posted. I used DB9 connectors to the servo drives from the Acorn controller.
To make things easier in the future for anyone else who wants this type of GSK AC Servo setup, I have attached the spreadsheet showing the connections to the servo drive, and the Acorn DB25 connections that work.
It's worth noting, even though it is mentioned earlier in this thread, that the servo drive must be configured to accept step and direction commands before starting. Step and direction goes by various names on servo drives, such as pulse and sign etc, but they are all the same thing.

Is it really over 3 weeks since I started? Thanks to Centroid's help, I managed to get the first servo working, but that was only the beginning of my saga, the second servo was a bit more difficult, but compared to the last AC servo driver, it was child's play. The last AC servo driver was to replace a failed GSK driver, and was a no-name chinese one. What a saga. There was no English manual of any sort. I didn't even know what signals were assosciated with what pin on the DB44 connector and I had no way of finding out, other than from an Aliexpress seller, who was trying to translate dribs and drabs from the Chinese manual. It's working now, but if there is ever an issue with it, I think the only solution will be to get another.
Anyway, onwards.....
I needed to install an encoder onto the spindle of the mill, so I sourced one (the same as the one on my lathe) and had no difficulty getting it to work when connected to the Acorn.
Mounting the encoder on the spindle is my current project, which I started a couple of days ago. Not as easy as you might think, any suggestions would be welcome.