[H.O]

Hi,
I'd like to hear from you what real-life speeds you have been able to reach with the UHU.

I initally started out with 3600 lines encoder which I knew was a bit much for the UHU but I now have a 500 line unit mounted and I can't seem to get above 400rpm without getting invalid counts.

400 * 2000 / 60 = 13.3kHz which is WAY below the 100kHz stated in the manual. ( Yes, I have the step-multiplier setting set to 0 )

The encoder is single ended but I have it wired to a DS9638 diff.driver and then a shielded twisted pair cable, about 1m long, shield connected to GND in the DB15 on the HP-UHU and only there. I've also tried with a 120ohm termination resistor across each pair at the DB15 but that didn't make any difference.

I've scoped the signals as they enter the DB15 connector and they look nice, sharp and uniform.

My motors are rated 2000rpm and my plan was/is to order 625 lines encoders from USDigital. I have a 2:1 belt reduction and 5mm pitch screws so that will give me a nice and even 1000 steps/mm and still stay well below the published 100kHz limit.

Right now I'm a bit bummed I will revert back to the higher resolution encoder and see if I get matching results with that one. In the meantime I'd appreciate if you could give me some info about you systems.

Thank you in advance!

/Henrik.