Centroid Community CNC Support Forum

I have plasma table I am retrofitting with Acorn. Generic NEMA23 motors and Leadshine DM542 drives. All drives raise the fault light when enabled right away. This table was running Mach 3, the drivers dip switches have not changed.

I have connected -Enable, -Step, -Direction to the Acorn and +Enable, +PUL and +Direction to +24v.

When I command a movement, Acorn lights its axis enable led, and 24V is measured across enable + and - at the drive. However, the DM542 raises the ALARM light steady.

The three DM542 manuals I've downloaded do not have an alarm condition where alarm is steadily lit.

Remember, these drives worked with Mach 3.

I have verified signals to the inputs on the drives are there, with the correct polarity.
I have verified the motor windings A/B are indeed paired correctly, A+ / A- shows 1.9 ohms. B+/B- shows 1.9Ohms. These may have been switched from the Mach instance, but they are still low ohm pairs. Regardless I can't get the motors to move, even in the wrong direction.

The drives go to fault as soon as enable +24v is raised.

Did you bench test per instructions before installing?
Also, you may need to wire those to a breakout board, versus direct to main board, most steppers require breakout? I am sure someone will steer you the correct direction.

Sounds like acorn not enabling your stepper drive if you manual jump the enable wire on the drive it should work
does your enable need a NEG or POS to enable .
if so then it matter of getting the enable line to work might need a relay card from the acorn
i don't really use enable with steppers in my builds on plasma i just leave it on

Yeah according to some other posts, apparently the DM542 is enabled by default. So I disconnected. Still no dice, but when powering on now I'm getting a caclunk kinda thing that I would expect, however.

I did wire this as much as possible according to the bench test, but the motors were/are in the machine, the bench test is "as installed".

I'll break out the oscope and see if I'm getting signals to the drives and see what they loook like. I did read sometthing about some internal jumpers in the DM542 that might need to be changed. The manual said adjust one of the three jumpers inside, but when I open it up, there's six.

Those drives are enabled by default and they wire to the DB25 per the schematics. They are 5v logic drives regardless of what you read in the manual. If they ever run at all from the headers you’ll more than likely start missing steps. Get yourself a breakout board from Amazon and wire them correctly, you’ll save yourself a lot of headaches. I have Leadshine DM542 drives on a router wired to the DB25 and they perform flawlessly.

I actually have a DB25 breakout. I'll do it now. Thanks!

Follow diagram S14976 and they will work.

i use the db 25 also on my gecko drives make sure the amp limit on the drive set correctly 2000 micro steps works good
also acorn use turns per inch to set motors not like mach 3