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I have an old lab device which prints it's result to a serial printer. I need to replace the serial printer with a computer. I have connected the device's 9 pin serial port to the computer's serial port, and started hyperterminal with the connection setting as described in the manual. The settings are as follows:

  • Printer interface
  • V.24 ( RS 232 C )
  • 9600 baud
  • 1 start bit
  • 7 data bits
  • 1 parity bit
  • 1 stop bit
  • output only, no control lines.

For some reason hyperterminal does not display any result from the unit. Is there something I am missing? Do I require a special serial cable? If I can get the result in Hyperterminal, I would be able to develop my C# program.

Thank you for your assistance.

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migrated from Nov 29 '12 at 2:00

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This is a hardware issue, not a programming issue. Stackoverflow is the wrong place for this question. – Daniel Mann Nov 28 '12 at 22:34
I have previously communicated with other serial devices with c#. For some reason I cannot read the output from the device which is meant for a serial printer. Thus I believe it is either a communication port setup, physical cable setup, or some communication which must first be send to the device to let it know it can transmit. – user1861429 Nov 29 '12 at 5:07
up vote 0 down vote accepted

Have you tried a null modem cable? It's a cable that has RX/TX cross connected. A pinout should be published somewhere.

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Thank you for the reply. I have purchased a serial data cable from our local pc store. Would that be a null modem cable, or must I ask specific for it? – user1861429 Nov 29 '12 at 5:09
Thank you for your help, the null modem cable did work. – user1861429 Jan 7 '13 at 7:11

I think what you're after is a Null Modem cable. You may have trouble finding one any more though.

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Thank you for the link; I will use the information to ask the pc shop to make up one for me. – user1861429 Nov 29 '12 at 5:13

If you are trying to simulate a serial device, you could try com0com to set up a virtual serial port.

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Thanks you for your help. I have downloaded it, and will test it today. – user1861429 Nov 29 '12 at 5:11

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