Quote Originally Posted by Doddy View Post
"Best" is such a funny word. DB9 are cheap and cheerful, but I doubt many think they're best at anything. Possibly not ideal for steppers, though if only an amp or so, shouldn't be too bad, but solder-bucket type (rather than crimp) are likely to fracture over time. A lot of us use the GX16s or GX20s for steppers. Question is - what's your environment - if not damp (e.g. coolant, etc) then you don't need anything too exotic. Really useful, in a paradoxical sort of way if you can e.g. swap stepper axis over (i.e. like-connectors without unique keying) - for quickly checking motors/drivers when you have problems, arguably similar for limit switches. My own strategy at this time - 4-pin XLR for steppers (high current capacity, very cheap from CPC/Farnell) and DB9 for signalling (just because you can get 3M 1-1 cables made up for peanuts).
I'm using the GX20's between drives and motors, and so far so good.
Ethernet for external signalling using small RJ45 modules at either end (they go into the control box through grommets).
Everything else is going direct connection.