[Phalanx]

Interesting as I used the same encoders(excepting for 360 instead of 250 counts) with another team. One was running at 6200RPM and the other at 7800RPM and didn't have any problems at all. Of course we use them at that speed directly attached to a Jaguar running in closed loop speed mode.

They do have tight mounting tolerances, and not a lot of axial play is tolerated, so the damage to the disks might be attributable to their mounting and axial play. How much axial play is there? How much vertical play is in the shaft? It could be too much vertical play that causes the disk to come down and scrape on the electronics board in the encoder.

The questions have been asked if you are decoding in 1X, 2X, 4X mode using the CRIO. It maybe that if you are doing 4X mode and using more than 1 of them you might be overrunning the counting ability of the FPGA CRIO. JHersh from NI on here is the expert on the FPGA rates of encoder counts. In fact there have been a couple of discussions on just how many and how fast the FPGA can handle.