rando@skipper.dfrf.nasa.gov (Randy Brumbaugh) (04/05/91)
My question is concerning hardware link communication. I would appreciate any help or experiences. The story: There are 2 t800s, "A" and "B". They are connected by a link. A uses robust (time-out guarded) link i/o. B does not. A sends a 1-byte command to B. B is not ready, so A times out and gives up and retries, repeatedly. Eventually B gets ready and tries to read a byte from the link. My question(s): Is there a time period when B can read the command and try to respond, even after A has timed out and given up? Should A reset the link after each time-out? When B gets ready, should it do a channel reset to be sure the link is "clear" before trying to to read? This is based on a true story. In the application, B takes about 4 seconds before it is ready to accept a command byte from A. If A tries before the 4 seconds, it never works. When we put a 5 second delay in the A process, so it waits until B is ready before trying to communicate, it seems fine. Not sure why this is. Randy Brumbaugh rando@skipper.dfrf.nasa.gov