Re: [CAD_CAM_EDM_DRO] Re: cable from PC to stepper drivers?????

cadcamcenter wrote:

> --- In CAD_CAM_EDM_DRO@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
>
> > I'd also recommend using a DB25 male connector on your "driver/PS
> box",
> > and a STANDARD cable ("1284", i.e., best printer cable you can
> buy).
>
> What is the difference between an IEEE-1284 cable and a standard one?
>
> extract from:
> http://www.pccables.com/cables/printer_cables.html
>
> What is the difference between an IEEE-1284 cable and a standard one?
> This is often a misunderstood concept. First, let's make the
> distinction between bidirectional and 1284-compliant cables. Applying
> the 1284 standard to cables, the IEEE-compliance primarily means
> speed, and these cables are precisely manufactured for that purpose.
> The 1284 standard sets exacting specifications on cable impedance,
> shielding, length, and connector styles to insure that they will be
> up to the task. Bidirectional cables must simply be able to transfer
> data in both directions, and your everyday 25-wire printer cables
> (and all straight-thru 25 wire cables) are capable of this; they are
> not, however, capable of the speed required by 1284-compliant
> peripherals. Peripherals which are IEEE-1284 compliant (such as many
> newer printers) require the use of a high-speed cable, as do most of
> the devices that connect to an EPP or ECP

Yes, and as far as printers, scanners, and other similar devices, that is fine.
But, the standard, I think, requires that several of the control and status lines
be on twisted pairs, but the data wires are NOT! For step/dir controls, though,
it is the data wires that NEED to be free of interference and crosstalk! So, an
IEEE-1284 cable may not be the best choice for this. I have found that I MUST
use IEEE-1284 cables for my devices that use the IEEE-1284 protocol for
communication with the PC. A standard printer cable messes up all the signals
with crosstalk.

Jon