In article .com,
"purple_stars" wrote:

and it runs
over an rs-232 interface USUALLY, but it doesn't have to.

Actually NEMA0183 has a Hardware Spec as well as a Protocol, and the
Layer 1 Spec is not RS232, but a previous spec to RS422, which is a
Current Loop running at 4800 Baud. The Previous NEMA0181 spec is
where the Layer 1 Spec was originally introduced. NEMA0181 was
designed to drive AutoPilots.

Bruce in alaska
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add a 2 before @