7i76 to software mode 2

When i measure between A or B and gnd i get 0 till i move the MPG. Then i get approx. 3v

5v i measure between gnd and Vcc

the Vcc is connected to pin 6 on TB3
the 0v (gnd) to pin 9 (also tried pin 1) on TB3
A/B to 16 and 17 on TB5

Did you measure the voltage on TB5 inputs 16, 17 (TB5 pins 1,2)
relative to field ground (TB1 pin 8) in both states of A and B?

The A/B voltage when moving is not very informative.
The A/B voltage should be close to 0V in one state and close to 5V in the other state.
if you read it when the MPG is moving you will get an average reading

Now i get confused.
but here is what you asked:
Between inputs 16 & 17 and field ground TB1 Pin 8 both give 0,1v. Then when i dial it in "it in the click" i get 0,4v.
Between pin 6 on TB3 and TB1 pin 8 i get 0v.
I get 5V between TB3 pin 6 and 1.
Between TB3 pin 1 and inputs 16 & 17 i get also 0v, only when i dial it "in the click" voltage is 3.3v

What confuses me is why do i need to ground with field ground? thats for the 24v supply right?

My 7i76 gets his 5v via the 5i25 card. So both jumpers are in left hand position.

Btw i also hooked up a different mpg handwheel with the same results.

And something else. I got some odd behaviour from the steppers when i set my servo period to 1000000. The steppers wont stop moving and making noise, after they the first requested movement.
Now i set it too 200000 and its ok. Should i adjust something else when i adjust my servo period?

1. The MPG inputs are field inputs so the MPG common must be common with field ground

2. If you changed the servo thread period, you also need to change the P term for the PID loop.
P term = servo thread rate so P should be 1000 for 1KHz servo thread

So, i need to ground it to TB1 pin 8?
Im getting lost...
Do i need to change the jumper w2?

You dont need to change any jumpers but the field I/O section is isolated from the 5V section of the 7I76, so if you use a 5V MPG powered from the 5V section you need to connect field common to 5V common.

In any case you must have ~5V signals at the 7I76's MPG inputs _relative_ to field common (TB1 pin 8)

Ah now i understand.
And it works! Hal meter is counting, steppers are ok again.
I just added a wire between Pin 8 on TB1 to pin 24 on TB3. Works like a charm.

Thanks!