Philip Cowley wrote:

> If I put the 2016s right by the encoders
> then I have a long parallel cable...
> But if I put them next to the PC then I have long leads
> carrying the quadrature signals... Very noisy.... Any ideas???

The quadrature signal wires sound the lesser problem.
Suggestion in order of convenience:

- Twisted pairs
- Co-ax
- Buffer to RS485 levels (0-5V complementary)
- Buffer to fibre-optics

The last point made me think: encoders sense the interruption
of light beams. Why not pipe these beams down fibre-optic cables
to photo-transistors, Schmitt triggers, HCTL 2016 chips etc
near the PC?

Shotgun-section fibre-optic cable would carry two signals
from one encoder. You still have to power the LEDs,
but as these are near motors this should not be a big deal.

Keith.