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Null Modem cables

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I have a receipt printer which the company says requires a null modem cable. I purchase said cable but it does not work. There is no specific description that it is “null” but it is the proper configuration DB9F to DB25M cable. Is this indeed a null cable. It appears I am obviously buying the wrong cable. Any help would be greatly appreciated.
Steve

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Null Modem cables

In reply to Null Modem cables

I suspect the problem is not the hardware (other than checking the obvious – like power). Check the configuration for the application that writes to that printer. Specifically, is it pointing to the correct port? Other aspects that controls the printing within that application?

Al Hedstrom

Null Modem cables

In reply to Null Modem cables

I have one cable that does work, therefore it can not be the app. Thanks anyway.

Null Modem cables

In reply to Null Modem cables

Check the RS-232 spec for a null modem. There are several – standard , full-handshake, etc. As a standard , usually the pinouts are 1 to 1,2 and 3 cross,pins 5 ,6 and 8 chain to 20, and 7 straigt thru to 7. Difficult to write this but most referencebooks will have a drawing.

Null Modem cables

In reply to Null Modem cables

Thanks

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