modem control on DEC DHQ11/DHV11

[George Robbins]

In article <1990Feb9.175317.17255 at eddie.mit.edu> neptune at fenchurch.mit.edu (Alan M. Steele) writes:
> 
>     Does anyone know about problems with the DHV11 driver in 4.3BSD unix?
...
> 
>     We have a MicroVAX II with a DHQ11 serial board and three modems
> (one of them is a Trailblazer) connected for uucp purposes.  We are
> running BSD4.3 with the standard DHV11 driver.  The problem we have
> encountered is that after a uucp connection closes, the DHQ drops DTR
> for the standard few seconds (I don't remember exactly how many) and then
> raises DTR normally.  With a few seconds after it raises DTR, there is
> a quick flash of signals (I have looked at the signals with a breakout
> box) and then DTR drops again and stays low, wedging that dialin line.

It sounds like you have two problems, neither specificially driver related...

1) With 4.3, you need to use the acucntrl facility to disable the getty
   running on the tty line, otherwise you have to dedicate a separate line
   that does not have getty running.

2) You don't have the modem properly configured as far as the modem control,
   echo and response codes.  You want the modem set up so that DSR and CD are
   only asserted when there is is a conection, not when in "command mode" and
   you want echo in command mode off, response codes on outgoing calls only
   and usually diable answer/reset when DTR is dropped...

-- 
George Robbins - now working for,     uucp:   {uunet|pyramid|rutgers}!cbmvax!grr
but no way officially representing:   domain: grr at cbmvax.commodore.com
Commodore, Engineering Department     phone:  215-431-9349 (only by moonlite)