None of the axis are moving - using mesa 7i92t with 7i76u

Hi All
Please can someone suggest next steps to try to get this to work.
I am a novice at this, so it must be something obvious, it’s just not obvious to me

Please see hal, ini, io attached.
I have a gantry X Y Y Z (two y motors)
I am using a Mesa 7i92TM connected from P1 to a Mesa 7i76U.
I have tried latest linuxcnc images on both Raspberry pi4 and on Intel NUC, and get the same outcome.
I used current version of mesact

The Linuxcnc dro counts on the screen, but the actual motors don’t move.
It looks like It counts in all axis until the software limits are reached, then errors.
When switched off, you can move gantry by hand in any direction.
When switched on, the gantry is rigid.
Stepper drivers are all DM556T.
Green led shows on all four of the stepper drivers (no red led on any of them)
I have wired from 7i76u to stepper drivers in differential mode, and in single ended mode with common ground, it made no difference, no axis moved.
The watchdog led in middle of Mesa 7i76U is green, and flashes approximately every second.
I have four inputs. Limit switches on the x and z axis, and proximity sensors on both ends of y axis.
In halshow, all four inputs are yellow, and go red if you trigger any of them.
Please can you suggest where to look next, or what config changes to try.
Many thanks

I would first try setting the step time and step space to 5000 (5 usec)
since 2500 (2.5 usec) is the drives minimum (0 margin)

Also check the 5V at the 7I76U to make sure its not low

Hi PCW
Thanks for your prompt reply
I changed the step time and space time to 5000 for all four motors, switched off everything, and restarted , however it makes no difference (the motors don't move)
I was not sure where to measure the 5v, but choose 7i76u's TB2 connector and checked axis 0 through 3 , using the ground and +5VP on each axis, and all measure 4.9v . (The 5v comes from the 7i92T).

Also you might try checking that the direction pins change state when jogging in either direction

(you will have to disable homing to do this test)

I am using a Mesa 7i92TM connected from P1 to a Mesa 7i76U.


In that case, the configuration file is incorrect. P1 is for the second 7I76
(which has stepgens 5 .. 9)

It's expected if you have a single 7I76, that it be connected to P2

Hi All

I have tried a few variations of wiring (but plugging it in to P1 surely didn’t help), more about that shortly.

I tried this

Mesa 7i76u TB2 axis to DM556T signal in.

Differential wiring:
GND
STEP- to PUL-
STEP+ to PUL+
DIR- to DIR-
DIR+ to DIR+
+5VP
(with ENA+ and ENA- on DM556T not connected)

I tried the same as above with
GND wired to ENA-
then
+5VP wired to ENA+
then
with both wired.


***************************
See Control Signals image which shows two different wiring for single ended.

I don’t know which type the Mesa 7i76u control uses, but I tried both of these.

Open-collector signal ties +5VP to PUL+ , DIR+ and ENA+
PUL- to PUL-
DIR- to DIR-

PNP signal ties GND to PUL-, DIR- and ENA-
STEP+ to PUL+
DIR+ to DIR+

***************************

Enable_disable image mentions this …

Enable signal:
This signal is used for enabling/disabling the drive.
High level +5V (NPN control signal) for enabling the drive, and low level for disabling the drive.

PNP and Differential control signals are on the contrary, namely Low level for enabling.

By default it is left UNCONNECTED (ENABLED).

***************************

tommylight wrote:

Do not wire Enable until you get things working.

 

Yep, on simple step drives, its a DISABLE input.