Light Machine Corp. Benchman XTr (retrofit)

U25-7 has +4.77 V, but U25-5 has 0 V.and if I'm reading this right, it looks like U25-5 is the power for the U10 microprocessor. Why would that be zero volts? U25-6 has +5 V. Just to be sure I probed U10-14 and was 0 V also.

In regards to the Tx and Rx signals at J2, the Tx signal at TP6 looks static, but Rx at TP7 looks much more "active",on the scope, if that makes sense?

If U25-5 is low, then the system thinks it is in the middle of a power fail.
U25-5 will only be low when U25-4 is below 1.25V.

Is TP1 +5V when referenced to TP19?
What is the voltage on U25-4?
If it is lower than 1.25V, check R1 and R2.

Attached is the MAX705 Pin Descriptions.

U10 power is through Pin 44(+5V) & Pin 22(GND).

It turns out I was measuring the wrong pins on U25. Pin 5 does have +5V, so it doesn't look like that's the problem.

I talked to tech support at Intelitek today and they do have a few of the ATC cards still in stock, for over $1000. And they need the old card in order to swap out the logic chips to the new card. So if the chips are the problem there's really nothing they can do.

Was there any chance they would test/evaluate yours?
I'm not sure why they would need your chips, they should have the programs. Perhaps it is the availability of the physical chips.
The last time I spoke with them, they still had a couple of the XT type machines there and were doing testing for others with them.

Yes, they will do a evaluation of the board for a pretty reasonable fee. They said they do have a working XT that they are able to test the ATC boards on. This is probably my next step.

I replaced the controller in my BenchmanXT and have it working well. I have to manually change out the tool but that is not really a big deal. Still, I would like to use the ATC. Everything works. If I set up the spindle and the height, I can activate the pnuematics and change out a tool. Here's my problem. I have the spindle running on a velocity PID. How do I index it to accept the tool? I could just take the pin on the spindle out and just rely on the drawbar, but I'm not sure that's wise. Any suggestions?

Thanks!

Well, I'm still trying to figure out what exactly the problem is with my ATC board and I think it may have something to do with the octal latches at U2 and U3. With the machine on and the program open the latch outputs are all floating between 1.8 to 2.5 VDC, even though the inputs are variously 0 or 5 VDC. When I open the ATC dialog box and try to move the platter down or unclamp the spindle I get the ATC command error message and the outputs on U2 all go to 5 VDC. Don, do you have any idea why it would be doing this?

Other then the outputs all going to +5V, it sounds like normal operation.
U2 and U3 outputs should be tri-stated until L_STAT signal "latches" the data and \RD_STATx becomes active and enables the outputs.
If you are getting the ATC command error, I suspect U10. You should be able to communicate fine. If you are communicating, the only error you should get is ATC in an unsafe state.
Looking back to your post of 6/22 with TP7 being active, I'm wondering if your wiring to J2 has Tx and Rx reversed.
Were you ever able to communicate to the ATC?

I can rotate the platter through the ATC dialog box; if I select say tool # 5 it will rotate the platter to #5. So it seems like serial communication is fine, at least in the Tx direction. But as soon as I try to command the platter down the software freezes up and/or I get error messages about communication errors or ATC in unsafe position. I double checked the proximity sensors for the platter cylinders and they seem to be providing good data to U7 ( 0 or 5 VDC respectively). But at U2 things get weird. Like I stated above, the outputs are all similar regardless of the inputs, which are either 0 or 5 V, and when outputs are enabled they all go to 5V, even if their input is 0 V. Perhaps U2-11 never goes low to "latch" the input data, or it won't go high to unlatch bad data it received when the RN5 went bad. I guess I could monitor that and see what happens. Does the output enable or RD STAT originate at U4?