Red Hat Bugzilla – Bug 79599
stty assigned timeout value is not acknowledged during async communications
Last modified: 2013-03-06 00:55:29 EST
Description of problem:
I am using an IBM Netfinity X-Series server and a Windows 2000 PC that is
running a Dawning Interface for Labratory equipment. There is a cable
connected to either com port on the back of the server and the other end is
connected to the serial port of the PC. We converted from an HPUX 10.20 to
Linux, hence the new IBM.
A COBOL application calls a file with the stty command embedded. This file
contains the following lines:
/bin/stty sane -parenb -parodd cs8 cread -clocal -ixoff </dev/ttyS1
/bin/stty brkint ignpar istrip -crtscts -echoe -echoctl </dev/ttyS1
/bin/stty 9600 icrnl ixon ixoff isig opost onlcr tab3 -echo </dev/ttyS1
/bin/stty -F /dev/ttyS1 -icanon time 200 min 0
This file is only called once until the application is terminated. Once the
application is started again, the file is then called again.
We are polling the 2000 PC for data from Lab tests run on serially connected
instruments. If the PC doesn't send a response, there is a twenty second
timeout period after which the application sends another poll to the PC.
We have used this same environment on the HPUX platform and it works just
fine. The results we are getting; the application doesn't recognize the
timeout value and therefore it keeps polling the PC on a continual basis. It
doesn't leave enough time for the PC to send data back to the COBOL
application. Also as a test environment to remove the 2000 PC, we set-up a
TI928 terminal to test the serial port on the server, the terminal will not
send any data back; the application didn't acknowledge the time out value and
still kept polling.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1.Connect a serial cable the com ports on the server and the PC
2.Start the COBOL application of the Server
The same results, the application continually polls the PC.
If the application on the server should receive acknowledgement from the PC,
the data transfer process would take place. After the data transfer, the
application on the server would poll the PC again. If the PC didn't send back
an acknowledgement, the server app would go into the 20 second timeout period
before sending another poll to the PC. However, if the PC acknowledged the
application poll; the data transfer process would take place.
This one is really old, sorry :( Is this still an issue?
there's been no update on this issue. If this is still an issue,
please re-open it.