Prototrak Plus Retrofit with Mesa 7i77 & 5i25 cards

4-20 mA is relatively common on VFDs but its not really usable with analog servo drives since its unipolar

Are you sure you have the analog inputs wired properly?

Are you sure the 7I77 is completely disconnected from the system? (you will damage the 7I77 if you apple power to its analog outputs)

Do you have drive manuals?

Thanks PCW! I am not completely sure if analog input (this is TB4) correct? The 7i77 was not connected except the other axis (DRV0 for example) and the encoders (TB4). When I applied the small amount of power it was at the amplifier/power supply. There are no manuals of use.

May thanks for the support!!

new2linux wrote:

lakeweb, Many thanks for all your time!! I can change directions, but cannot change speed. Have not tried the battery, you are describing the wires going from DRV0 take one at a time and go between battery and ground?

Ok, skip the battery for now. As I understand it, if you reverse the power supply, the motor reverses. If this is so...

If you step up the voltage does the motor go faster? And note, if you have the current limiter set all the way down, you may not be stepping up the voltage. Are you also reading the voltage when you step it up?

UPDATE:
And you wrote:

new2linux wrote:

At 1.4 shows no amp value until I go up in voltage, to the next value.

What does this mean, next value? Is this a digital readout power supply? Please use a volt meter and watch the voltage out for yourself. Something sounds fishy. Especially as Todd pointed out, it is strange that you need so much voltage to make this move. And, I have no experience with torque mode, could that be the set up here and it takes that much toque start the motor????

Best, Dan.

Many thanks, Dan! next value is 1.5, yes digital power supply. I will use volt meter next time, I have a few things going on for the next few days but will return soon. What should the current or voltage (not completely shore of what I an seeking, maybe advise) be set to regulate, so I don't goof something up.

Many, many thanks to everybody for there help!

Many thanks to all who have help with this project! I have applied .04 a @ 16 v in low setting (on the hi/low) saw no speed change. The meter reads a very small amount different than the read out of the power supply (low amp setting .5v p/s = .58 at the meter, 5.1 p/s = 5v at meter, on the other end of scale 30 p/s = 28v at the meter)

many thanks!

Where are you applying this voltage? ( and why would you apply more than 10V to a +-10v input?

What is the part number of you motor drive?

.040 A input current means you likely have the wrong drive input wiring

Many apology. My intent 1.6v.

For pic of drive look at link or try paste:

forum.linuxcnc.org/media/kunena/attachme...712/IMG_0742_1-2.JPG

MagneTek
Motor drive p/n 15028R
p/n22241000
model: 4020D-143

many thanks!!
Motor Data Sheet

No, that is the motor, and it has nothing to do with the drive other than it is powered by it.
You should be applying your test voltage between two of the terminals on control input of the amp (With regard to servos that are more complex than a simple amp often called the "drive" because it is what drives the motor.)
Here in the old thread you took a picture of the terminal in question.
forum.linuxcnc.org/media/kunena/attachme...21712/IMG_0813_1.JPG
In that picture either the red and green wires, the red and white, or the white and green is the pair you need to apply the test voltage to. You need to test to see what does what.
You will also have to have the two terminals that were connected with the black jumper wire connected by a jumper to enable the amp (drive).

My many thanks go out to: Todd Zuercher, andypugh, tommylight, PCW, lakeweb and bevins for your invaluable advise, unwavering support, humor, honesty and it is with great regret there has been a most regrettable error on my behalf and I have managed to goof up the "x" axes of the amplifier. Todd the pic you referenced is correct as to my method with exception a meter was placed where the variable power supply gator clip-on leads came together with a length of the gray with red plug. No smoke, I think it is very likely when I turning off variable power supply with protrak amp connected.
I have no change in the lights on the protrak amp as to to indicate any error, but cannot get the servo to move at the same value (in the 1.4 to 1.5v range) from "x" & "y" currently, only the "y" axis will move. I have looked at plug interface to cabinet, swapped out center (see link the big blue cylinder in the center) capacitor with its psb, checked the fuses. I did not want to wait any longer to get this out. I would truly like to thank each of you for your time. I will be looking for another ebay I fear. If there is something I am missing?

forum.linuxcnc.org/media/kunena/attachme...21712/IMG_0816_1.JPG

Many, many thanks to all!
Thanks to the forum!

I don't remember if you said what parts you replaced after your first accident with miss-wiring the transformer.
Did you replace, or repair one or both of the servo amps? Which one? Did you have to spend a lot to find a replacement?

It may be advisable to just cut your losses with these old amps that are undocumented, rare, and probably difficult and expensive to replace, And get something that is common, well documented and easy to use. Something like these.
www.ebay.com/itm/ADVANCED-MOTION-CONTROL...6:g:nm8AAOSwtfhYpmhg
or
www.ebay.com/itm/AMC-Advanced-Motion-Con...3:g:O9gAAOSw65FXs2Za
and a simple power supply should work for you.

Hopefully if someone has a better idea for a better amp replacement they will chime in.