[Hooked_on_Scares]

~30 feet - RS232 (Serial port)
~15 feet - USB
> 1000ft - DMX (RS422/485)

You might be able to stretch more out of these, but these are the specs. I'd put servo signals in the RS232 category, since the physical level is similar.

If you're going for a long run, I'd reccommend either DMX or a USB extender. Both of these are differential, which allows longer signal runs without degradation.

- Hook

 

[Hooked_on_Scares]

PMT,

I don't have all those connections myself. It sounded like you were looking for some info on how long is safe. I've only been responsible for animation wiring for the past 2 years. And, in that case, the controlling computer is on the second story, whereas the skulls are in the front (grave)yard. Because that run was going to be so long (~150', maybe?), I decided DMX would be the only way to go.

In this case, there's a USB-to-DMX converter (short USB cable), then the other end of the converter connects to a length of CAT6e (I think. Whichever is the shielded variety). At the skull-end of things, the CAT6e connects up to some DMX-servo control and lighting boards. The final servo run to the skulls is maybe 10'.

Hope this helps,
- Hook