Hardware flow control on EPORTS

[Colin Dykstra]

In article <4171 at cfctech.UUCP> alexb at cfctech.UUCP (Alex Beylin) writes:
>
>Is their a way to setup a port of an EPORT card on the 3B2/600
>for hardware flow control?
>
>The only way we found to fix this is to eneble hardware flow
>control on the 3174 async ports.  Then, we have to enter the
>following commands on 3B2 as soon as the user logs-in.  
>(i.e. we detect if it is a vt100, which 3174 attempts to emulate
>and then do hardware flow setup):
>	
>	stty -ixon -ixoff -ixany 
>	epstty hfc
>
>Now, all the stty stuff can be done from the /etc/gettydefs,
>but how can we setup a port on an EPORT card for the "epstty hfc"
>mode?  The way things are done now, users who dial-in with vt100
>emulations are not very happy.
>
I have had similar problems with our internal implementation at
AT&T Canada.  We needed hardware flow control for high-speed laser
printers (38,400 baud) as well as high speed modems.  

I can think of at least two ways to do the "epstty hfc" command:

1)	Add to the command to /etc/profile
	This is executed by all users when they
	login.  You could "case" for specific terminals
	or ttys.

2)	Daemon executed by "rc" at boot-time:
	This is the approach that worked best for
	our implementation.  Below, please find sample
	scripts.

In /etc/rc2.d create a a short script called S98hfc.  Something like:
###################
# SCRIPT TO START 
# HARDWARE FLOW CONTROL
# SHELL SCRIPT:
# /usr/local/fixline
###################
nohup /usr/local/fixline & >/dev/null 2>&1
echo "Staring HFC Daemon"

The actual script "/usr/local/fixline" looks like:
#####
#
#	FILE:	  /usr/local/fixline
#	PURPOSE:  To set-up and maintain
#		  hardware flow control on
#		  a named set of eports ttys
#
#		  Colin Dykstra
#		  AT&T Canada Inc
#		  uunet!attcan!colin
#####
TTYS="tty41 tty42 tty43 tty44 tty45 tty46 tty47 tty48"
TTYS="$TTYS tty61 tty62 tty63 tty64 tty65 tty66 tty68 tty71 tty72"
LOG="/tmp/linestats"
while :
do
  for i in $TTYS
  do
    if [ `epstty -a </dev/$i` = "-hfc" ] # check to see if hfc is off
    then	
      echo "Turning on hfc for $i"	>>$LOG 2>&1 
      epstty hfc </dev/$i	 	>>$LOG 2>&1
      epstty -a </dev/$i	 	>>$LOG 2>&1
      date				>>$LOG 2>&1
      echo "============="		>>$LOG 2>&1
    fi
  done
sleep 30
done


I hope the above helps...


-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Colin Dykstra                       | The opinions expressed herein
uucp:    {uunet,utzoo}!attcan!colin | are my own and do not necessarily
attmail: !cdykstra                  | reflect the policies of my current
voice:   416 756-5098               | employer.
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