🚀 go-pugleaf

In article <870306-103725-1768@Xerox>, denber.wbst@XEROX.COM writes:
> I need some help in a big way here.  All I want to do is set up some
> modems so users can dial in to our MicroVax-II.  We're running Micro-VMS
> and have a 16 port Emulex multiplexer board.  It took the phone company
> 5 tries before we had our phone lines working (but that's another
> story).  The first problem seems to be the modems. 
   [many sob stories omitted - wsy]

I have a MicroVAX II with a DHV-11 multiplexor board.  Connected
to this via a 25-line straight-thru cable is a Scholar 2400/1200/300 baud
modem.  It works fine except when the power glitches badly; the
uVAX rides out the glitch just fine, but the modem sometimes decides
to not answer the phone- ever.  This has happened twice in three 
months. Power cycling restores the modem to sanity.
	
The configuration on the modem line is /MODEM/HANGUP/AUTOBAUD.

The DTR down/up is due to the uVAX thinking it saw something 
come from the modem (possibly a text message).  VMS responds to the
characters by printing the welcome banner and Username:.
If it doesn't get a valid user/password pair in thirty seconds,
it toggles DTR to tell the modem to drop the line.
	
You can get the modem/uVAX into an infinite loop this way, 
(each one sending the other an error message, and getting an
error message back).  PBX data switches do it easily.
This crashed our local data switch- IBX S40's can't deal with 
a DTR toggle every thirty seconds.  The cure was to set the
line NOMODEM on the data switch (NOT the dialup modem lines)
	
Hope this helps.
	
	-Bill Yerazunis
	"People at the door, Daniel.  Police, Daniel"