Hi

This is an extension of the quick comms question. Apologies if not all the
information is relevant to this list.
I'm trying to talk to a Datamax label printer on the serial port.
The printer manufacture has let me know that the protocol is Xon Xoff for
this device.
If I send a simple command such as <stx>k (is serial port there?) I get a
response from the printer. (Y)
If I query the status of the printer <SOH>A the printer responds with
NNNNNNNN<CR>
The moment I send a longer string such as the command to print a label, the
printer stops responding and appears to go into an error condition where it
thinks an image is being downloaded to it. I can only get out of this
condition by switching the device off. If I send the same command to the
printer using Hyperterm (after writing the command to a file , coping
contents and "paste to host") the label is produced.
This is driving me crazy. As the label is produces using hyperterm, there is
nothing wrong with the command, I assume there is nothing wrong with the
cable either (home made cable - any one have the specs for a rs232 cable to
device that supports xon/xoff) or hyperterm is working some kind of magic
that my code isn't. It even works with hyperterm when I turn handshaking
off.

I am setting up the dcb block as follows

 case EHandshakeSoftware:
  dcb.fOutxCtsFlow = false;     // Disable CTS (Clear To Send)
  dcb.fOutxDsrFlow = false;     // Disable DSR (Data Set Ready)
  dcb.fDtrControl = DTR_CONTROL_DISABLE;  // Disable DTR (Data Terminal
Ready)
  dcb.fOutX = true;       // Enable XON/XOFF for transmission
  dcb.fInX = true;       // Enable XON/XOFF for receiving
  dcb.fRtsControl = RTS_CONTROL_DISABLE;  // Disable RTS (Ready To Send)
  dcb.XonChar = 17; //(Ctrl Q)
  dcb.XoffChar = 19; // (Ctrl S)
  break;

This serial class that I am using currently is that of Ramon de Klein
([EMAIL PROTECTED]) as my own class has not been used with XonXoff before
and I thought the error may be in that code. apparently not.

What else should I be looking for to try and get this printer to recognise
the communication?
Well this is essentially a serial port question, I am getting quite
desperate and any additional advice will be helpful.

Hylton




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