Prototrak Plus Retrofit with Mesa 7i77 & 5i25 cards

If you have the amps working again, the next step is to start connecting and confirming the connections of the control wiring (7i77 to the amps). First thing is to make sure that the amps are disabled when Linuxcnc is placed in e-stop and machine off, next make sure they are enabled (powered up) when Linuxcnc is in machine on. Now is also a good time to make sure that things like limit switches and other inputs and outputs are working.

Next make sure the encoder feed back is correct. (DRO in Linuxcnc is working.)

Finally make sure your analog signal wiring is connected from the 7i77 (QAn,/QAn) to the terminals you connected your DC test signal to on your amps. (I'm a little surprised it took as much as 1.5v to get any movement. Do you know how much current was used? Make sure the resistance between those 2 terminals on the amp is more than 2000Ohms.)

Now you should be ready to start tuning the PID loops.

Todd, many thanks! The estop is an in line before the power supply, (old school red button). I am using 2 transformers (24v & 5v to power field voltage to TB1 & TB2), both show lights working, there are no limit switches or other outputs.

The DRO works in the "linuxcnc mode", I believe it is close and the correct direction.

The analog signal wiring are the ones going from the low side of the amp/power supply (on Prototrak all one) to the DRV0 & DRV1, these are in the very 1st terminal location and 2nd terminal location on both DRV0 & DRV1. I am not completely shore what (QAn,/QAn) are, but I am checking now?

many thanks!

QAn and /QAn are the terminals on the 7i77 for the analog control signal wires. For example QA0 is pin #1 on TB3 of your 7i77, and /QA0 is pin#2.

Many thanks Todd!! I believe all the TB3 signal wires were tested and teased out for the proper location in my earlier (prior to the miss wire) and I think a big part of that you helped with. I can research how we got the current locations if needed.

many thanks again!

Hi new2linux,
Do you have the servo amp make and model? As Todd says, that is a strange voltage requirement to make the motors move.
Best, Dan.

This is the only info out there, on this model:

www.southwesternindustries.com/media/manuals/24923_manual.pdf

I am working to verify the voltage and amp settings, keeping in mind the max amp is no more than 2000 Ohms. as per Todd's suggestion.

In that manual, page 68, 69, there is a picture of the motor drive module. There should be a make and model number on that module.
Best, Dan.

Many thanks lakeweb! I don't know if there is any other info out there. This is on the power supply.

SouthWestern Ind.= Manufacture
ProtoTrak Plus=model
15047= part #
MD1-M1568=serial #


Many thanks for all the help!

Ok, looks like Prototrak is not giving on this thing. So you have three gray cables? How many wires in each? Three? How did you pick which wires to energize? Did you look inside the box?

I realize you are not well practiced with electrical circuits. But you really need to know what the wires do. It almost sounds like this has a differential input and you are applying voltage to ground and one leg. And that is why it is taking so much voltage to move the motor.

Best, Dan.