[Jerryv]

Hoping someone here has some insight on this. It is a bit of a puzzle.

Background: I have quite a bit of troubleshooting experience but none with the DX-32 control. I am trying to help out a friend with an older machine that was sold and then repossessed so the history is a little lacking. The machine is about 1995 vintage with a 386 based control and Siemens 611 drives.

The problem first seemed to be a drive issue as the Z axis would fault as soon as the drives were enabled so I started down that path. The drive fault indicated a possible wiring problem, but I couldn't find anything wrong and in the process of checking we found that the drive didn't fault if one of the limits were activated. I finally found the wiring diagram and disconnected one of the limits. Then I could jog the X, Y, and Z with no errors through the "jog off limits" function. I thought maybe one of the switches or wiring was shorting to ground dropping out the 24V, but more checking found this wasn't the case. (the limits are a little odd in that there is only one per axis and they are in series) In doing a little more reading, I found the following in the manual: "If any one of the limit switches is open, 24Vdc is removed from the coils of the reversing contactor, turning the spindle motor off." I don't see anything labeled as a "reversing contactor" on the diagram so perhaps this is referring to an older system? In any case the limits go into the AUF board which I don't have documentation on. I am wondering if the spindle drive may be causing the fault or if there is something else that powers up at the same time that could be causing it? Is there any documentation available on the AUF board?

If anyone has any insight or information on the AUF board, I would appreciate it. If I posted it in the wrong forum please let me know which one is more appropriate.

TIA
Jerry

[Jerryv]

Finally got some time to investigate this further and thought I would update this thread in case anyone else encounters something similar in the future.

My friend has a 760 with a similar control, but the manuals had been improved by the time it was made. I found a good explanation of the e-stop string in it. The limit switches, drive ready contacts, and a couple of motor overloads are all in series to provide 24V to the e-stop relay. The ground to the relay is supplied by the BMDC board. The AUF board has a transistor that can supply the 24V and will do so if a limit is activated so you can jog off the limit. The manual stated that this transistor remains on for 30 seconds when activating the drives, but I saw no sign of that. The X, Y, Z, and power module ready signals are all in series and go into one input on the AUF board so the control has only one drive fault error message.

A little more background; the machine was set up with a fourth axis rotary which wasn't connected. My friend didn't think it needed to be but it had been used in the past. He wasn't sure if there was a setting or anything to enable/disable it. This drive was indicating a fault since the motor wasn't connected, but the ready signal from it goes into a separate input on the AUF board and since it was an option, I wasn't sure it was needed. There was a C axis showing on the position display.

I jumpered the ready signal from the main drives and still got the same drive fault error message. I then jumpered the fourth axis ready signal and finally the controller was satisfied. The X, Y, and Z would home and jog like they were supposed too. Oddly, the C axis display disappeared. As a test, I shut everything down and connected the rotary, removed the jumpers and restarted. It worked again and now the C axis display was back. Somehow the controller must sense the rotary, but doesn't really ignore it if it isn't there. I think in the future, the rotary will just have to stay connected all the time.

The diagnostics on these machines are quite limited. A few LEDs in the right places would have helped me a great deal. Or a separate message for the fourth axis would have saved a lot of time. No one really appreciates good diagnostics until they need them and find them lacking.

Jerry