Problem with handshaking

[Xavier MIGNOT]

Hello,

After moving this week-end our serial printers from a D380 to a K360 system, it seems that the XON-XOFF protocol is not working (or configured) well. To stay exactly in the same configuration, I picked the 'dumb' model from the D380 (on wich it worked fine) but on the new system we meet printer's buffer overflow with printouts larger than 2/3 pages

My interface file include the following statement :
'stty raw 9600 -parenb cs8 ixon -istrip clocal <&1 2>/dev/null'
Is there anathing else to do (or to check) in order to configure xon-xoff handshaking for serial printers ?

Any help or suggestion will be greatly appeciated.
Thanks

Xavier

HP-UX 10.20
HP9000 K360

[Steve Steel]

Hi


Possibly there is a change in cables required.


What was the old interface card. Is it the same as the new


steve Steel

[Rodney Hills]

Your stty looks good. I assume you are using the serial ports on a mux card.

Is it possible the printers configurations themselves got xon-xoff turned off?

It is also possible that since the K360 is a faster system, the printers themselves may not be able to respond fast enough when their buffers near overrun. The correction for that is to either lower the baud rate communication on the printer and the serial port, or change the configuration on the printer to send the xoff sooner (based on percentage its internal buffer fills).

Hope this helps...

-- Rod Hills

[Xavier MIGNOT]

Steve:
Thanks for your reply !
I only use 3 chanel cable (TD/RD/GD); the printer begins printing correctly...I suppose it would be able to send and receive the XON/XOFF signal by the same way too.

On the D class , I used an eisa mux. On the K class, I use a J2092A.

Rodney:

Thanks for your reply too!
I don't think the printers are loosing their xon-xoff configuration... they have been working on the D class without any pb during a cup of years

[melvyn burnard · Accepted solution]

Just a thought. I have seen an occasion before wherew a move like this was done, with the same results.
Turned out that the cable had one wire broken, with the result that the system was sending data to the printer, the printer tried to send Xoff, but due to the one pin being disconnected, this was NOT getting back to the system to stop the data flow.
As I said, just a thought

[paul courry]

Just FYI.......

Xon/Xoff protocol is distance sensitive. Round trip across 3,000 miles is about 160 milliseconds I've found. This means I need to reduce the baud rate to 1200 to keep to overflowing the buffer on HP2563 printers on long print jobs.

(The Xoff has to travel to the HP9000, be acted on then empty the pipe before you are truly Xoff'ed.)