Stepper motor powering on but no motion

I have LinuxCNC 2.9.1 running on a raspberry pi 400 with Debian 12 "bookworm" (just for bench testing will update to desktop when I get everything installed on actual machine) and wired to a Mesa 7i96s.

The 7i96s is connected to a Stepperonline DM542t and then to a Nema 23 stepper motor set as the X-axis.

I have everything installed and ran the mesa config tool and show a connection to the 7i96s.

When I power everything up I get power to the stepper motor, I know this because it gets frozen and I cant spin it.

The 7i96s is wired to the driver as follows:

step0---> Pul-

Step0+ --> Pul+

Dir--> Dir-

Dir+ -> Dir+

I am not sure where to start in trouble shooting this and any insight would be helpful.

Thanks.

The most common reason for no motion in step/direction
systems (assuming correct wiring) is too-short step lengths.
I would try setting the step length to at least 5 usec

I connected a multimeter to the dir+ and dir- ports on the 7i96s and I get a 5 volt reading. When i try to jog the machine there is no change in the reading.

So if you jog in different directions, you get no change in the direction output for that joint?

If that is the case I would verify the hal/ini files joint mapping and
also check for watchdog bites (red light on 7I96S)
Do you get any errors?

I reinstalled linux cnc and started from scratch and I am getting errors.
Unexpected realtime delay on task 0 with period 100000
Run the latency test and resolve before continuing
hm2.hm2_7i96s.0: error finishing read! iter=6

"Unexpected realtime delay on task 0 with period 100000"

If 100000 (100 us) is your actual servo thread period, this should
be increased to 1000000 (1 ms) or even 2000000 (2 ms) for a RPI4

Also the RPI 4 typically needs isolcpus=1,2,3 and force turbo to get
decent latency

Ok, I've searched a good amount how to do the isolcpus and force turbo is there a good reference anywhere on how to do that?

There's probably info in a thread here but I was able to
find out about force_turbo and isolcpus by googling for:

rpi isolcpus
rpi force_turbo

Awesome thank you

i had the same issue when i first hooked up these drives. these drives have a dip switch setting from the factory being set at 24V on the step and direction signals. switching to 5V solved the problem,