hi
i wanted to know how exactly handshaking signals (RTS and CTS) be included in the program.
we are using a wavecom modem that use AT commands.
we have also included MAX232 for ttl to rs232 conversion.
command to accept call is ATA. i wanted to know whether to trasmit ATA command as a string through Serial port(TXD) or transmit chatracters A,T,A separately or is there some other equivalent code that is being transmitted when using the hyperterminal
Thanks
Hey Iyer configure your serial port in NULL modem and you won't have to worry about any handshaking signals once you are done with it transmit your at commands serially character by character and don't forget to transmit "ENTER" after each command and try searching these forum threads a little there are lot of similar topics Best of luck
thanks for the help..
i'll try that out and will let you know
bye
how exactly to configure the serial port in NULL modem
No, a Null-modem cable is not what you require here:
A so-called "Null-modem" cable is what you need for connecting two DTEs together.
What you need, if you're not going to implement hardware flow control, is to loop-back the modem's CTS output to the modem's RTS input - see:
www.wavecom.com/.../viewtopic.php
"don't forget to transmit 'ENTER' after each command"
There's no such character as 'ENTER'.
AT commands need to be terminated with a Carraige-Return character - ASCII code 0x0D.
See my post titled "AT Command Termination Character" (21-Mar-2007 20:14) in this thread: http://www.keil.com/forum/docs/thread9483.asp