Mesa 5i25 and 7176 getting started

It is mentioned on page 18 of www.mesanet.com/pdf/parallel/7i76man.pdf

Hmm, very briefly, not much detail to go on for a newbie

hm2_5i25.0.7i76.0.0.enc0.count
hm2_5i25.0.7i76.0.0.enc1.count

Should change value as you move your mpg. (Machine->Show HAL Config in the Axis GUI)

Ok, well I've just used Hal configuration for the first time... lol, Its pretty cool, I can see my inputs for limits etc that I'm testing

However, the enc0 or enc1 don't seem to alter? I've got gnd and +5v from pins 1 and 6 on TB3, then I'm wiring my A B signals into pins 1 and 2 (inputs 16, 17) or 3 and 4 (inputs 18, 19) on TB5, but don't get a count from the hm2_5i25.0.7i76.0.0.en0.count or hm2_5i25.0.7i76.0.0.enc1.count pins. Like I say I'm getting my other inputs working though, so something is going right... haha!

Can you see the encoder input pins changing state? The inputs should still be available even though they now double-up as encoder quadrature.

No they don't change state... I've brought my volt meter back home so I can check whats going on. Will update shortly

Ok, I've checked all connections and voltages, from pins 1 and 6 on TB3 I get 4.85V, which I presume is enough for my MPG?

In HAL Configuration I've loaded up hm2_5i25.0.7i76.0.0.enc0.count under the watch tab and the value doesn't alter from 0.... I have seen it briefly change to 1, but there is no consistency to that, its only changed a handful of times for a split second, no pattern of rotation will alter it. I have used the MPG on another board with mach3 previously and it worked ok then. I can't check this tonight, but I will check asap!

Any ideas?

Also, what should be the exact code be to change the 7i76 mode from 0 to 2? I've used sserial_port_0=2000xxxx, but I can't see exactly why the pattern of (0's) and (x's) changes from mode 0: sserial_port_0=00xxx ??? why the extra 0's and x's?

The critical things needed are:

1. The MPG A,B pins are connected to inputs 16 and 17 (or 18 and 19) these are the 4 bottom pins of TB5
2. The MPG outputs ~5V signals, that is check that both A and B pins read high (>3.5V) and low (<1V)
relative to field ground at different MPG positions when connected to the 7I76 inputs
3. The MPG common (ground pin) is connected to Field I/O common

Note, you normally cannot read the states of the MPG inputs (via a xxx.xxx.7i76.0.0.input-nn pin)
that are driven by a 5V MPG, the input bits still have a VField/2 threshold
the MPG inputs with the 2.5V thresholds are only used for counting.

The definition of the sserial config string is in the hostmot2 manual page:

man hostmot2

1. The MPG A,B pins are connected to inputs 16 and 17 (or 18 and 19) these are the 4 bottom pins of TB5
2. The MPG outputs ~5V signals, that is check that both A and B pins read high (>3.5V) and low (<1V)
relative to field ground at different MPG positions when connected to the 7I76 inputs
3. The MPG common (ground pin) is connected to Field I/O common

ok, I have my mpg on inputs 16 and 17 (pins 1 and 2 on TB5).
The MPG voltage in only around 0.5v when moving the handwheel? I'm getting my mpg 5v fromTB3 pin 6 and gnd from TB3 pin 1. My field voltage is 24v so can't connect to that.
When you say the MPG common or Gnd do you mean A- B- to field Gnd or the actual MPG gnd to field Gnd? In the latter case I get 0v at pins A and B??

I'm totally confused

Note, you normally cannot read the states of the MPG inputs (via a xxx.xxx.7i76.0.0.input-nn pin)
that are driven by a 5V MPG, the input bits still have a VField/2 threshold
the MPG inputs with the 2.5V thresholds are only used for counting.

So even if my MPG is working correctly, I won't be able to monitor it in Hal config?

ok, I have my mpg on inputs 16 and 17 (pins 1 and 2 on TB5).
The MPG voltage in only around 0.5v when moving the handwheel? I'm getting my mpg 5v fromTB3 pin 6 and gnd from TB3 pin 1. My field voltage is 24v so can't connect to that.
When you say the MPG common or Gnd do you mean A- B- to field Gnd or the actual MPG gnd to field Gnd? In the latter case I get 0v at pins A and B??

MPG GND to field ground

If you get 0V on A/B when MPG GND connect to field ground
that probably means your MPG outputs are open collector and
will need external pullup resistors (say 2K) to 5V to function

So even if my MPG is working correctly, I won't be able to monitor it in Hal config?

You can monitor the count, but you cannot monitor the A/B states via the xxx.xxx.7i76.0.0.input-nn pins

will need external pullup resistors (say 2K) to 5V to function

So where do the pullup resistors go exactly?