Switches, Hubs, and Modems
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stty and xmodem

Tim Downs

stty and xmodem

I have two server with the exact same modem on each server. xmodem transfers work fine on one (test server) but is hit or miss on the other (production server). I believe it has to do with an stty setting. Small files work fine (under 1024) but files larger than 1024 work only 25% of the time. When it fails I always get a 15 (negative acknowledge) and it tries to resumit the same last block a data a number of times before it fails completely.
I believe it has to do with an stty setting but I'm not sure which one. The following stty settings are different between the two servers

working server not working (prod)
eof = ^A eof = ^D
parenb -parenb
cs7 cs8
hupcl -hupcl
-clocal clocal
-ignbrk ignbrk
ignpar -ignpar
istrip -istrip
icrnl -icrnl
ixon -ixon
ixany -ixany
isig -isig
icanon -icanon
echo -echo
echok -echok
opost -opost
onlcr -onlcr

The modem config file is has the following setting:

Modem init string is:

The modems are USR Courier HST Dual Standard
Which one(s)(stty settings) would I change?

Would just issuing the stty -isig < /dev/tty2a1 make the change permanent?

The other protocol that I send in is ANSI and that works for all our other trading partners.
Mohieddin Kharnoub
Honored Contributor

Re: stty and xmodem

Hi Tim
You have probably an issue with stty settings since its not working for large files > 1024.

why don;t you have a look at this link and check your settings:

Good Luck
Science for Everyone