[thingstodo]

The PLC5/60 is reading the encoder signal (or count) once every 10 ms and appears to be keeping track of the revolutions that the drill is turning

1260 rpm is what the PLC calculated for a speed. I have to dig through my pile of tools and locate my tachometer to measure out the actual speed.

1260 rpm is 21 revolutions per second. At 1024 pulses per revolution, that's 21504 pulses per second. Every 10 ms that is 215 pulses. It's not clear if that works out to 21.5 Khz or if the A and B channels add, for 43 Khz.

The IK card states that it can deal with 50,000 Hz. That works out to 500 pulses in 10 ms, just under half of a revolution. 50 revolutions per second is just over twice the speed that my drill is turning (or that the encoder shows that the drill is turning.

More testing tomorrow.