Serial port problems...

  • Thread starter Thread starter Tamir Khason
  • Start date Start date
T

Tamir Khason

PLEASE HELP,
I already seat on it a vouple of days, but no solution yet.
Someone, Please help!!!
I have to manage some device, working with RS422 (have a converter). From
one place it working form my program it does not!
Architecture:
-----------
device |RX]-------RS422------|converter]------RS232-----[TX][My program]
[OLD
]------RS232-----[RX][ ]
-----------
The old program sending to my program (listener) some binary sequenses, the
program TRANSFER AS-IS those sequenses via RS232/RS422 converter to the
device - THIS DOES NOT WORK!, however while I'm connecting the old program
to the device it works fine.
What is the problem??? I just transfer bytes as-is (checked with sniffer),
but it does not works...

PLEASE ADVICE
 
Tamir Khason said:
...
The old program sending to my program (listener) some binary sequenses, the
program TRANSFER AS-IS those sequenses via RS232/RS422 converter to the
device - THIS DOES NOT WORK!, however while I'm connecting the old program
to the device it works fine.
Click to expand...

Possible reasons:
- your app could work with the wrong baudrate/other comm settings
- the old app could use some "mean tricks" like break states, signals on the
dtr/cxr lines
- last but not least it could be some timing problem: If I got you right
your app relays both data sent to the device and coming from the device;
This will certainly change some timing aspects - maybe the old app simply
fails to work because of some timeout?
What is the problem??? I just transfer bytes as-is (checked with sniffer),
but it does not works...

PLEASE ADVICE
Click to expand...

My advice would be to create a "T-cable" that splits the tx line of a serial
cable so you can connect it to two different PCs; That way you can inspect
the data flow with and without your program in the middle, and probably find
the difference.

Niki
 
Back
Top