[comp.sys.dec] DS3100 serial port problems

brook@ut-emx.UUCP (Brook Milligan) (02/24/90)

I am trying to connect the modem port of a DS3100 (Ultrix v3.1/UWS
v2.1) to a hardwired serial line for uucp/tip use via a Micom
linedriver.  At this point all I can get when I `tip micom' is the
message `connected (/dev/ttyd0)' followed by nothing.  The linedriver
and serial line work fine with a PC so I suspect either my cable
connection to the linedriver or my /etc/remote file or ...  Has anyone
done this or something similar?  Can you offer suggestions?

I wish to use this for outgoing connections only so I have no gettys
on this port.  The relevant portion of /etc/ttys is

ttyd0   "/etc/getty std.9600" dialup	off 		# modem line

and the relevant portion of /etc/termcap is

sd|du|dialup:\
	:tc=unknown:
su|dumb|un|unknown:\
	:am:bl=^G:co#80:cr=^M:do=^J:nl=^J:

The relevant portion of /etc/remote is 

micom|hardwire:\
	:dv=/dev/ttyd0:\
	:br#9600:\
	:el=^C^S^Q^U^D:\
	:ie=%$:\
	:oe=^D:

The cabling goes from the DS3100 to Dec H8571A adapter to convert the
6 wire cable to a regular DB25 connector.  This adapter is to connect
the following pins:

	Dec MMJ connector		DB25
`	1 DTR				20 DTR
	2 Trans. data +			2 Trans. data
	3 Trans. data -			7 Signal ground
	4 Recv. data -			7 Signal ground
	5 Recv. data +			3 Recv. data
	6 DSR			{	6 DSR and
				{	8 DCD

The linedriver expects only the signals trans. data, recv. data,
signal ground, and DTR (i.e., pins 2, 3, 7, and 20).  At the advice of
local communication gurus I connected pins 6, 8, and 20 between the
Dec adapter and the linedriver; however, the same thing (i.e.,
nothing) seems to happen if I connect them straight through.

Have I miswired these cables?  Am I using the wrong device file
(/dev/ttyd0)?  Is /etc/remote misconfigured?  Is there another file I
must configure? ...

Any suggestions would be greatly appreciated!  Thanks.
-- 
====================================================================
Brook G. Milligan                   Internet:   brook@emx.utexas.edu
Department of Botany                Bitnet:     bohk313@utaivc
University of Texas at Austin       UUCP:       ...!ut-emx!brook
Austin, Texas  78713   U.S.A.       (512) 471-3530
====================================================================

chris@mimsy.umd.edu (Chris Torek) (02/24/90)

In article <24976@ut-emx.UUCP> brook@ut-emx.UUCP (Brook Milligan) writes:
>I am trying to connect the modem port of a DS3100 ....

What modem port?

The built-in tty ports on the DS3100 are virtually useless for anything
but hardwired lines, as they implement only receive and transmit signals.
(They also, it seems, cheat on the output levels.)  Although you could
connect these ports to a dial-out modem, you would never be able to tell
if it lost its connection (no DTR).
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@cs.umd.edu	Path:	uunet!mimsy!chris