we are having a problem while interfacing a gsm module with 8051, we are able to correctly interface gsm module and 8051 with pc seperately.but while both are connected together we are not able to sent or recevie any message....is it because we have two rs232 connected...?,one on 8051 board and one on gsm module..... plz help us to solve this.....
Sorry, but you haven't really managed to describe what serial ports you are talking about. What is connected to what?
Two serial ports on the PC? Or two serial ports on the 8051 (in that case - does the used processor have multiple serial ports?) Or do you use a GSM module with multiple serial ports?
If you can't find how to describe with text, then do use ASCII art to show connections.
Two serial ports on the PC? Or two serial ports on the 8051 (in that case - does the used processor have multiple serial ports?) Or do you use a GSM module with multiple serial ports? Or all 3 connected together
Erik
"Or all 3 connected together"
Yes, but that implies my questions. If you make a chain - which device is in the middle and have two serial ports?
After all, RS-232 don't support a star topology so either one of the devices is in middle with two serial ports - or yet another unknown device have three serial ports - one for PC, one for modem and one for 8051.
I know that, but if the OP has all 3 connected/tied/wired together it is not the first time someone has done so.
The source-code formatting tags will be required; eg,
+-----------+ | | --->+ +----> <---+ +<---- | | +-----------+
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