At 10:24 AM 6/7/2003 -1000, you wrote:
>Aloha,
>
>Boy are those guys fast! I ordered one with PS and antenna
>on Wednesday; I think I phoned to Florida.
>
>It was delivered early Friday afternoon!
>
>I have my "breakout cable" prepared. Found an old DB25
>cord with an M on one end and F on the other. Just
>opened it, and cut all the wires EXCEPT the
>2, 3, and 7 (for RS232) wires. So only the TD, RD and signal
>ground go through. I note these are exactly the same
>pins used for these signals on the hp RS422 connector.
>
>Can I just now connect them together, or are they different
>voltage levels; thus the need for the "interface" unit
>previously discussed?? Guess I don't understand what
>the interface system does, unless it is a way to either
>rid or sum together the "other" signals from the hp rcvr.
I think the interface levels are different, and the proper
way of dealing with RS422 is with separate grounds for each
datapath.
I don't know if it is necessary, however.
RS232 is very forgiving, so I doubt you'd do any harm in connecting
them, but... you may have to switch 2 and 3 to get a null-modem
connection. As for the (B) lines mentioned in the diagram, I don't
know if they're necessary for RS422 or not. That PDF I pointed you
to should let you know... If nothing else, plug in a breakout box or
a bare DB25M into the clock and take measurements on the various pins
relative to pin 7. Should let you know.
Eric
>However, I have neither powered up the unit, nor connected
>together pending either getting an interface unit or learning
>that the thought above is correct now that I have all else
>coming out the hp connector "blocked".
>
>73, Jim KH7M
>
>
>
>_______________________________________________
>TenTec mailing list
>TenTec@contesting.com
>http://lists.contesting.com/mailman/listinfo/tentec
--
Eric F. Richards
efricha@dimensional.com
"The weird part is that I can feel productive even when I'm doomed."
- Dilbert
|