Replacing Advanced Motion Controls "brush type 12A8 with "Axcent" amplifier

Ok, First address the enable signal. When you power the machine and start Linuxcnc, and the motor moves, what is the order of what is happening? Are the drives powered before Linuxcnc is started? (this is ok if it is what you want). Do the drives start moving now? Are the drives powered up after Linuxcnc is started? Do the motors move before Linuxcnc asserts the enable signal or after? If they are moving before the enable signal is asserted, do they stop when the enable signal is sent? It might be that the signal needs to be inverted either at the drive (dip switch SW1-5 on the drive) or in Linuxcnc.

Once you have that working we need to look at why you are not seeing encoder feedback in Linuxcnc. Can you post a copy of the hal and ini files you are currently using? In the wiring drawing you posted a few posts back, it stated you had the X encoder connected to TB3 pins 1-6 that would be for encoder.00. But in the last hal file you posted you had the X axis configured for encoder.04. That would explain the no encoder feed back, if it is how you still have it connected and configured.

Todd, Many thanks!! As I start the CPU is running linux mint. If I start linuxcnc w/o power supply on will get debug message attached. I apply power to power supply, no motor motion; when linuxcnc is running with logo up, motor no motion; when I click on the left (F1) button at the top, no motion; when I click the right button (F2) motors will run, click right (f2) and motor will stop, motor is not locked, will turn with your hand.

many thanks!!

Yes, that sounds like the machine enable is working and correct.

The motor runs away because there is no encoder feed back (or it isn't being seen) and the drive and PID are not tuned.

Many thanks, Todd!! Attached are the .ini & .hal that I was using.

If you have the encoder connected to the encoder.00 inputs on the 7i77, I have no idea why you can't see any movement of the DRO. Double check your wiring.

I thought at one point you had the encoder feedback working (with the old encoder). I don't know what you may have done to cause it to stop working, or why you felt it necessary to replace the old encoder. (Did you do something to damage the old encoder? And if so is it possible what ever damaged the old encoder also damaged the 7i77?)

Todd, you have been so very helpful, and I an ever so grateful. If you feel that the 7i77 needs replacing, I will get that ordered. I need the 2nd opinion to be confident. many thanks

Edit: 7i77 card is on order, 2 day shipping option was used.

I don't think it is time to just give up and order a new card. I think we first need to figure out what is going on. There may be nothing wrong with the 7i77, or it does have 6 encoder inputs if you don't need them all. Even if you did hurt the 7i77, you should try to figure out what you may have done to cause it's demise (so you don't do it again.)

Maybe Peter from Mesa will chime in with some diagnostic help and these cards are often repairable and Mesa can usually repair/exchange a damaged card for less than the cost of a new one.

Many thanks, Todd!!! The order is on the way, I expect to see my 7i77, next week. I will gladly work on the current 7i77 card, I have not pulled it out of cabinet. Many thanks, Todd, for your expertise.

You could try connecting the encoder to other encoder inputs on the 7i77 to see if you can see any readings from it. Check that the encoder 5v out from the 7i77 is good. Try the encoder only connected to the 7i77 (not also connecting it to the drive).

Try checking the encoder's signal with a volt meter. Just connect the 5v and ground to a 5v source then with the meter probe from the A to ground, while very slowly turning the encoder. You should see some fluctuation of voltage. Then do the same from B to ground.

Todd, Many thanks for your expertise! This is how I used temp wires to use the 5v transformer at (TB1) (unplugged from 7i77 card) to supply 5v to the (TB3) encoder plug (unplugged from 7i77 card) at TB3-3 (GND) to TB3-1 (A) and then a 2nd to TB3-4 (. The 7i77 card & drive were not part of this test. The digital meter ranged from on A=4.74 to 4.80 & B=5.20 TO 5.27, the fluctuation was not dependent on moving the encoder or motor. W/o any motion to motor the meter moved around. When turning motor slowly the meter just did not look to be connected. The meter range was in the 20 range (the other ranges were 2 or 200).

Many thanks, Todd, I am grateful for your help!


(I do not know where the smile face came from)

New card delivery is late Monday (up to 9:00 pm)