linda wrote:

> Hi All
>
> I am doing a project recently requires RS232 communication between a
> hpux workstation and a robot. This machine has its own RS232
> communication protocol which can accept commands and return result
> from queries. The RS232 connection requirement is very simple.
>
> the workstation the machine
> 9 pins connector 25 pins connector
>
> Pin 2(Rx) connected to Pin 2(Tx)
> Pin 3(Tx) connected to Pin 3(Rx)
> Pin 5(Gnd) connected to Pin 7(Gnd)
>
> Ive wrote a C code to control the machine. Apparently, the machine is
> accepting the commands from the C program and performed its tasks, but
> wouldnt response to the queries that Ive sent from the program.
> Therefore Ive probe(pin2 - Tx) from the 25 pins Dsub connector and
> found that the machine is actually returning the expected result but
> the serial port is not set to read the result. The read result return
> -1.
>
> I am not a RS232 programmer and this is the first time I am doing so.
> But I think it must something to do with the RS232 options that I
> should set in my hpux box.
> All kinds of RS232 related helps are appreciated. Thanks in advance.
> ~

Most problems I see with new RS232 setups are that most unix implementations
give a login-session (getty or such) on each found serial port. If you use the
serial port for other purposses than a terminal-login be sure to disable this
login. See your inittab file ("/etc/inittab" ?) for your situation.


CBee