im having a problem with communicating between two computers through a serial interface using hyperterminal. i have checked each computer with a serial loop cable (RX pin connected to TX pin) and anything i type in the hyperterminal window echoes back.
but when i connect two computers using the same cable and then type a letter on one hyperterminal window then it doesnt show on the other. both computers have the same settings; 9600 bps 8-N-1 and no flow control
am i supposed to do something else. am i missing something???
I'm probably out of my depth here...its good to know you've checked with loopback though, that would have been my first suggestion.
Assuming both comps work with loopback, then its most likely a software problem. Or maybe even an error in the baud in one of the comps (so loopback still works, since it receives and sends with the same baud).
What are the OS's of the two computers? XP can sometimes be a tad annoying, even with hyperterminal.
Davood Amerion, the connections are exactly as you stated.
one computer is running Win98SE and the other is running WinXP Pro
Edit:
one more thing, the computer running Win98SE is a laptop and the voltage levels on the serial port are between -5.5V to 5.5V whereas the voltage levels on the desktop running WinXP Pro are -10.5V to 10.5V
There is one issue in win 98, check this also: in WinXP you cannot change the serial port settings (port no., baud, data bits, stop bits, parity) unless the port is disconnected. In win98 you can change these settings even with the port opened, but they become effective ONLY after a disconnect/connect cycle. Also (stupid remark, sorry), make sure you are working with the port where the connector is inserted...
one more thing, the computer running Win98SE is a laptop and the voltage levels on the serial port are between -5.5V to 5.5V whereas the voltage levels on the desktop running WinXP Pro are -10.5V to 10.5V