Re: bridgeport boss convertion quesitons

[Jon Elson <jmelson-at-artsci.wustl.edu>]

Fred Proctor wrote:

> Bridgeport stepper folks,
>
> Matt sent me a GIF file of Table 4-6, "Axis Drive Signal Sequence,"
> which shows the high-low bits that move an axis forward or reverse.
> There are three columns: SMD input pin, SMD output pin, and motor lead.
> The SMD input pins shows pins 13 and 19 and a two-bit Gray code. The SMD
> output pins show pins 4, 8, 28, and 24, and a non-Gray coded 4-bit
> sequence. Motor lead pins are 1, 2, 3, and 4 and also show a non-Gray
> coded 4-bit sequence.
>
> Which of these should the EMC stepper task generate? I expected a 4-bit
> Gray code sequence, but none of these fits the bill.

The pins 13 and 19 are probably the phase signals, and are probably
what needs to be sent to the driver.  Only two bits should be needed
to drive the stepper.  I'm sure they were conserving parallel port bits
back then, too.

Jon