I'm resubmitting this message in plain text for the reader's 
convenience. The First posting came up too confusing with the html 
mark-ups. Sorry for the inconvenience.

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I was just admitted to the Community Project and I'm a novice, at best, 
in QNX.

I am setting up a RTOS lab at Ferris State, using Momentics over 
several different platforms to program companion Neutrino nodes.

The Neutrino (x86 w/ BIOS) nodes are connected to small lab robots 
through an RS232. I've stablish basic communication with open() 
function (fcntl.h). Accordinng to robot doc, I need to sent the string 
with command syntax (cr at the end), and immediately after, read the 
content buffer which should have <0cd>, indicating syntax error, <1cr>, 
indicating successful reception of command, and <2cr> if a "stop" 
button in a hand-held keypad is pressed during command 
transmission/processing by the robot.

When I open the port (/dev/ser1) I do so with O_RDWR)

Problem is: I can never get out from read()  O_NONBLOCKING is clear, or 
I always get <-1> when  O_NONBLOCKING is set.

This is the open() segment when O_NONBLOCKING is set:

    if((fd = open ("/dev/ser1", O_RDWR | O_NONBLOCK)) == -1)
    {
     fprintf(stderr, "Error with open() on /dev/ser1.  Make sure 
exists.\n");
     perror (NULL);
     exit(EXIT_FAILURE);
    }

Any clue on what I'm beating my head against here? Should I delve into 
something different like readcond()?

Please, let me know whta direction I should take.

 

Thanks in advance,

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Luiz Costa
ELECTRICAL/ELECTRONICS ENGINEERING TECHNOLOGY - COMPUTER NETWORKS & 
SYSTEMS
College of Engineering & Technology
915 Campus Drive SWN 405
Big Rapids, MI  49307
231.591.3086 Phone - 231.591.2271 Fax