Connecting a glass linear scale to linuxcnc

A low resolution interrupter should be fine
a 1024 PPR encoder not so fine

Todd Zuercher wrote: In that case, if you are only using it for calibration, and will not rely on it for production (removing it). It should not matter if it is slow.

3600 is most likely your latency and is quite good. I would think you'd might able to run a 10000ns on that, if the PC is fast enough that it doesn't bog down user-space too much. (I'd have a hard time believing any pc could run a base thread that fast.)

FURTHER UPDATE
I can run reliably with a base thread of 20000 with no RTAI errors and no missed steps by eye.

I've also emailed leadshine asking them what the maximum inputs a second the inputs can take. Once I know I'll update here for confirmation before I buy the scale.

Thanks all so far