Fanuc Serial Pulse Coders - Red cap servos, mesa 7i76e, how to?

Is it possible to run all these things together: 

Mesa 7i76 E  ---- 7I84 (Isolated remote field I/O card). Will use it to output quadrature signals to the Ultra3000s, it will generate this quadrature output from the Fanuc encoders [is this possible?], remaining I/O used elsewhere. 
                               
                         ---- 7I85 (4 Channel encoder 5 channel Serial RS-422 interface). Will hook up the 4 Fanuc redcaps to 4 of these RS-422 ports. And the encoder inputs are good to have around incase I want to add linear scales (2 axis) and maybe two MPG wheels.  image missing /media/kunena/emoticons/cheerful.png

Sure would be great if this system worked because it happens to be two fairly inexpensive boards. Canadian dollar isn't so great right now image missing /media/kunena/emoticons/grin.png
I would be pleased to have those encoder inlets, too. 

Progress pic from a little while ago: 
 

Yes, you can use 7i76E with 7i84 with a cut in half LAN cable (see manual for wiring), and 7i85 with a IDC26 to DB25 cable (available on Mesa stores and even some older PC's have them, look for a parallel port on the back slots). BTW, 2 of 7i85 could be used as 7i76E has two IDC26 headers, or similar boards, and you can add more 7i84 or 7i79 or 7i71 or 7i72 to 7i85.

Thanks for confirming this, I haven't used multiple Mesa boards at once before. What a great system.

You are welcomed, always, and welcome to the "dark side" !
Used them once, worked MUCH better than advertised, got unbelievably good support from PCW, used them ever since, a lot.

I have received the additional Mesa boards and am putting some thought into the system and wiring.

I was thinking that I would use the encoder signals to generate commutation signals to output to the Ultra3000 drives. The drives have inputs for Commutation Channel S1, Commutation Channel S2, Commutation Channel S3. 

The question I have is: do I need to worry about torque ripple if I am providing the drives with only commutation pulses in this manner? If so, should I be outputting something else from LinuxCNC to the drives such as quadrature encoder pulses generated from the encoder signals? 

Trying to avoid getting this all wired up and then having to change it. 

My other option would be to output TTL incremental encoder pulses from LinuxCNC (is this conversion from absolute serial encoder data to TTL incremental possible?) out via the 7i84 into the Allen-Bradley Ultra3000s.. I'm starting to think that this is more of a failsafe path because its unclear if the drives will run motors on commutation signals alone. Here's a look at the manual pages regarding [standard] feedback into the Ultra3000s.  

 


Thoughts and speculations welcomed and encouraged.