7i84u - Mode 2, MPG and power connections

Trying to free up the high speed encoder function on my 7i96s by moving the pendant wiring all over to a 7i84u and might as well move all of the other pendant wiring over at the same time.

I read that if I run the 7i84u card in "mode 2" there are 2 spots on TB2 that set up as encoder channels (inputs 16-19)
Would that be two separate A/B single ended encoders or is that one A+/A- B+/B- differential like I have on the 7i96s ???   The pendant MPG has differential output

it also says that the thresholds automatically go to 2.5v to be compatible with MPGs.
Is that's regardless of field power level or not?

Currently I have Field A and B both at 24v, my original thought was  to use the split field power option and have field A be my 24v and move all of the axis selection, jog rate, e-stop pendant inputs  as well as the existing prox limit/home and output onto TB3
Then make field B into 5v and move all of the pendant wiring over from the 7i96s to TB2. I could tap into the VFIELD power input block TB1 for my power and ground for the pendant. I end up with a pile of 5v IN/OUTs that I'm not sure what to do with but maybe later


For switching to MODE 2, software selectable so from what I understand:
what I currently have in the HAL
loadrt hm2_eth board_ip="192.168.1.121" config="num_encoders=1 num_pwmgens=1 num_stepgens=3 sserial_port_0=0xxxxxxx" 

changes to:
loadrt hm2_eth board_ip="192.168.1.121" config="num_encoders=2 num_pwmgens=1 num_stepgens=3 sserial_port_0=2xxxxxxx"  



Anyway, looking for any input before I blow up my second 7i84u
Thanks





 

That looks correct except you do not change the number of encoders:
"num_encoders"  as this only applies to high speed encoders, not sserial devices.

Thanks for that clarification (never would have figured that one out)
Any guidance on the change to mode 2 creating two separate A/B single ended encoders or one A+/A- B+/B- differential ?
Thanks
M

There's no current way to support differential inputs on the 7I84/7I84U
I would just use a differential encoder single ended (just use A+,B+)

That's what I figured to try first. Wiring it up to make a 5v Field B right now and then I'll move the MPG over and try it
Thanks again,
M

(Just realized I posted this into general instead of under boards, maybe I can get someone to move it.)

I got just the encoder itself moved over to the 7i84u
#net jog-counter <= hm2_7i96s.0.encoder.00.count
is now
net jog-counter <= hm2_7i96s.0.7i84.0.0.enc0.count
and it's working as it should

But these lines don't seem to work anymore or I'm referencing them incorrectly
#setp hm2_7i96s.0.7i84.0.0.enc0.counter-mode 0
#setp hm2_7i96s.0.7i84.0.0.enc0.filter 1
From what I'm reading those don't exist on the 7i84u in mode 2
Something I need to do some other way or something I don't need to worry about ?
M

These are parameters that apply to normal high speed encoders:

#setp hm2_7i96s.0.7i84.0.0.enc0.counter-mode 0
#setp hm2_7i96s.0.7i84.0.0.enc0.filter 1

Not sserial devices

There is a count mode parameter for sserial MPG counters so you can choose 1x mode or 4X mode

I'm just using the default x1 for this but good to know for down the road.

I've finished moving all the other inputs over and they are all working again. Tomorrow I'll get the outputs moved over and then I can work on getting the spindle and it's encoder connected which is what started all of this in the first place.
Simulating a VFD / encoder on the bench is proving to be a lot more work than I originally thought.
M