Another DYN4 and Acorn Losing Steps Issue

[martyscncgarage]

Just when I thought I had gotten out of the Screw Terminals vs DB25 woods. I think I am having this issue to the more I think about a few random cuts that dropped a hair low. I blamed it on a possible tool offset being wrong. But in hindsight I don't think it was. I am not looking forward to having to pull my mill back out from the wall to get back to my electronics after I just leveled and calibrated it all finally.

2 questions:
1) If you remove/replace the resistor in the DMM Centroid cable SHOULD it still work on the screw terminal outputs?
2) Since the original schematics originally didn't indicate I would have to use the DB25 head my acorn board is mounted in a tight spot that I don't have much room to come off with a DB25 breakout. Does anyone know of a good right angled connector or breakout or cable to use in a tight space?

The attached DYN4 schematic works....

S14888-ACORN_rev3 DMM DYN4 SERVO DRIVE.pdf

(98.54 KiB) Downloaded 137 times

[slodat]

I was losing encoder counts (steps between Acorn and DYN4) using that schematic. The thing that solved this was the DB25 step and direction signals.

[qjones]

The attached DYN4 schematic works....
S14888-ACORN_rev3 DMM DYN4 SERVO DRIVE.pdf

So since I already have the DMM DB25 cable I would still need to remove the resistor than connect to my +5v power supply? Which I am kicking myself because I kind of hated the voltage drop configuration anyway to the DMM considering I have a true +5v just sitting there waiting to be connected to.

Thanks,

[martyscncgarage]

The attached DYN4 schematic works....
S14888-ACORN_rev3 DMM DYN4 SERVO DRIVE.pdf

So since I already have the DMM DB25 cable I would still need to remove the resistor than connect to my +5v power supply? Which I am kicking myself because I kind of hated the voltage drop configuration anyway to the DMM considering I have a true +5v just sitting there waiting to be connected to.

Thanks,

No resistor required if you follow the Centroid schematic.
Use the 5vdc.
You could contact DMM and ask for the correct resistor value. They have made a change. See my post on the forum about this issue.

[DICKEYBIRD]

Does anyone know of a good right angled connector or breakout or cable to use in a tight space?

I'm using this one:
https://www.amazon.com/Signals-Breakout ... 1-fkmrnull

[slodat]

Again, I was losing steps between Acorn and DYN4 using 5v and the screw terminals.

viewtopic.php?f=60&t=2814&start=20#p20394

[martyscncgarage]

Again, I was losing steps between Acorn and DYN4 using 5v and the screw terminals.

viewtopic.php?f=60&t=2814&start=20#p20394

Respectfully, I understand you were having issues. I've not had those issues and it's worth allowing someone else the opportunity to check it out. If there is an issue, collectively it's worth all of us trying to replicate and subsequently solve the problem.

You had the problem, but why?

Marty

[qjones]

Does anyone know of a good right angled connector or breakout or cable to use in a tight space?

I'm using this one:
https://www.amazon.com/Signals-Breakout ... 1-fkmrnull

I've been all over amazon looking. Never saw this one. It looks almost perfect for my needs.

Thanks!

[Richards]

I can't duplicate the problem when using my single DMM DYN4 750W servo. I'm using the DMM cable with the 2W resistor that Marty showed in a video a few months back. I am NOT using 5VDC. Everything is connected to the H2 connector, as instructed in the DMM wiring diagram that was sent to me when I purchased the drive, the motor and the necessary cables.

Just because I can't duplicate the problem does not mean that there is no problem, but at least on my test bench, everything is working as expected.

[slodat]

... If there is an issue, collectively it's worth all of us trying to replicate and subsequently solve the problem.

You had the problem, but why?

Marty

I agree. This is why I went to great lengths to perform the same test, changing one thing at a time until the problem went away. I test and troubleshoot for a living. As I have stated before, I was posting my results in hopes of helping the manufacturers, and others experiencing the same lost steps problem. While I do not know the cause, it is apparent the DYN4 works well with the DB25 step/direction signals on machines it has problems with the screw terminals. The why.. I don't know.

Again, my intention is to contribute to this community.