Can not get stepper motors to move with Gecko g250x drivers

I guess I have lost everyone's interest or at least exhausted their list of suggestions.  I want to thank Tommylight and PCW for their help!  While the issue remains unresolved, they both helped me move forward in my understanding of LinuxCNC.

I have not given up on the Gecko G250X, but I must get this controller working ASAP.  As such, I have ordered DM556T stepper drives, which others seem to have working with LinuxCNC and Mesa boards.  Unfortunately, it will take a few days to get them.

I hope the DM556T will be more plug-and-play than the G250Xs seem to be.  Of course, this means I have to rearrange and rewire half of the control box.  Maybe I will get it right this time!  I still need to figure out outputs as they seem to be NC when I thought they would be NO. 

No, not yet, i am just to damn busy, sorry for that.
I still think there is something not right with the wiring and all the jumps through the cabling, so if you are willing to investigate further, use a DVM set to measure resistance and check:
-if the G250 has the same gnd for step/dir and power
-if the signal gnd is the same with Mesa signal gnd
pretty sure the last one will not be 0 ohm, but do check that and report back, powered off when measuring.
If it does end up not being 0 ohm, use a 10-100 ohm resistor between the G250 gnd and Mesa signal gnd, then power on and test.

Ok, so not sure what I am testing here, if I test from any gnd (power or signal) to earth I get about 0.3 Ω, from signal gnd to step or dir I get about 18.9 kΩ.

I use the term “about” to indicate the measurements flicker 0.0 to 0.3 but settles around 0.3 and for the other 18.88 - 18.93 but settles around 18.9.

Is that what you were suggesting I check?

Mesa TB1 pin1 should be gnd
G250 screw terminal from your reply should have common on pin 30
Check those two points, they must be 0 ohm or thereabouts as DVM usually show 0.1-0.3 ohm for dead short.

TB1-1 to G250-30 tests "mostly zero", that is my DVM shows 00.0=>00.1=>00.2=>00.1=>00.0, spending most of the time reading 00.0. My DVM shows the same sequence if I hold the two test leads together so I presume that is as close to zero as it can test.

Sorry, is that with the machine fully powered down?
-
Another thing to test, when the machine is powered on, use the DVM to measure first DC voltage between those pins, then AC voltage between those two pins.
Should be 0V to max 0.1V to allow for measuring errors.

The numbers I provided previously were the same with the machine powered or not, maybe slightly more zero when powered on.

AC Voltage 0.000 => 0.002 V (no idea why this is expressed in V vs mV)
DC Voltage -0.0 => -0.1 mV (not sure why negative, as even switching leads gives the same negative readings)

So, as I mentioned previously:

I have not given up on the Gecko G250X, but I must get this controller working ASAP.  As such, I have ordered DM556T stepper drives, which others seem to have working with LinuxCNC and Mesa boards.  Unfortunately, it will take a few days to get them.

I ordered the DM556T last week and they got here late today.  Doing a quick test without changing any of the existing wiring other than to disconnect one G250X.  Because the G250X uses 4 leads for power and motor phase connections, I just wire nutted three of the leads on each of the split cables and nutted the signal GND, since the DM556T seems to only uses the motor power GND. I wired up one DM556T using the single lead of each of the slit cables and I added the Step - and DIR - connection.  Ran pncconf wizard, using most of the values I did for the G250X, other than not selecting the G540p as the driver.  And ...

Test motor turned both directions without issue.  It is difficult to tell if my setting are correct, but I can work on that when I have everything wired.

Next,  I need to gut my control box to swap the DM556Ts in for the G250Xs!

Again, I wish to express my appreciation to TommyLight  and PCW  for their help.  I know I still have a long way to go, but at least I feel I have moved forward.

Thanks

moretoyswins wrote:

S
Next,  I need to gut my control box to swap the DM556Ts in for the G250Xs!

I would rather get a new box, less work and leave the existing one as is since it works with GRBL, or rewire for parallel port maybe? I know i would!

I've been holding my tongue all this time. I have observed many people failing to get the Gecko's going. Whilts it is evidently possible, the additional cost vs a DM556 or similar is just not worth it. I would try and sell it to a Mach3 user