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PMAC-PC and PCWIN-32 startup - 2 motors turning?
#1
My boss acquired an awesome but older machine tool from Oak Ridge. It is an X-Y granite table with Anorad DC-brush linear motors and Heidenhain scales. I am hooking up a DT PMAC-PC running under Windows 98 with PMAC-Win32. The PMAC-PC has the 80Mhz CPU, 8-axis and DPRAM options. The PMAC-PC is connected to a DT PMAC-NC front panel (via J3) and a couple ACC-8DP I/O boards (via the 2 JMACH cables). This is really old stuff (I apologize in advance) but the machine itself is one of a kind and worth the effort. If I can make it work we will buy all new (supported) motors/scales before using the machine for any production work.

I have one of the encoders working, the Y-axis. The second encoder, the X-axis, is flaky unless directly connected (bypassing the cable harness) so the encoders are OK. I just need to fix an in-line encoder preamp. I think I can get that working. The limits are working but need some post-processing. There are 3 flags but normal +/-/home are boolean functions of the 3 physical flags. I think I can generate the expected indications with some PLC functions. The Z axis and A axis are unconnected (so far).

This is my big question. I can move the Y-axis (open and closed loop) but there is something funky going on with X. Even with I100=0 the X motor is being commanded to move whenever Y is commanded to move. I can see it with a meter on the inputs of the amplifiers (Aerotech 4020s, remember these are ancient brush type linear motors) What the heck is going on? Can control channels 1 and 3 be logically connected in a way not described in the manuals? Can they be combined on my ACC-8D?

Any help/hints are most appreciated.
Keith
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#2
There are several ways in which PMAC could be configured to do something like this. We would need to see your configuration to determine what that would be. If you could send your configuration to support@deltatau.com we may be able to help you.
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#3
(10-02-2013, 05:01 PM)steve.milici Wrote: There are several ways in which PMAC could be configured to do something like this. We would need to see your configuration to determine what that would be. If you could send your configuration to support@deltatau.com we may be able to help you.

I did a full reset (I think - used a sequence from the manuals) and ran the wizard to gen basic configurations for 2 motors. I can't imagine what the problem might be. BTW - the encoders and flags work fine now. The cables from the glass scales were too long and the signals routed through out-of-spec (not shielded twisted pairs etc) cabling.

Thanks so much for the reply. So I create a .cfg file that saves all settings and send it to support@deltatau.com? I will do this tomorrow - thanks!
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#4
Sorry for the delay - been travelling for work and having a difficult time getting files off this machine. The configuration file is attached and I sent it to support@deltatau.com.

TIA


Attached Files
.zip   fordt101013.zip (Size: 12.71 KB / Downloads: 5)
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#5
Your configuration does not have any settings that would cause this. My guess is that there is an electrical fault that causes this. A common cause is loss of ground on the amplifier causing it to float above ground level.
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#6
Thanks Steve - I will look into the grounding issues between the amplifiers. It sure looked like a signal was being applied to both amplifiers from the PMAC but I'll try to isolate and confirm things.
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