Mesa 7i29 Maximum Encoder Count Rate

Hey all,

I'm upgrading the encoders on my servo motors, and will probably go with the US Digital E6 models, but I want to make sure I don't over specify CPR for the drive/FPGA combination I'm using.

The motors are 1 2000 RPM and two 2500 RPM DC brush servos. The ball screws are of unknown pitch at this point, either 4 or 5 TPI. I'm using a 7i29 with a 6i24-25.

A 10k CPR on the 2500 RPM motor would be 1.667 million counts/sec, and on some of the other servo cards this is the theoretical maximum with filtering enabled. I'm just not sure how close I want to be to that theoretical maximum.

Cheers,

Pete

With a 6I24 and encoder filtering enabled (and assuming non-muxed encoder counters) the maximum count rate
of the hosttmot2 encoder counters is 4.4 MHz. To get clean signals at that speed is going to require differential signaling

Awesome, thanks PCW. I am going with differential signaling encoders. I'm very new to this so please excuse the basic questions.

What would be a reasonable CPR for my case (older VMC?)