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I have a data collector device which has a RS-232 male port, and the PC which sends data to that device has also a COM (RS-232) male port.

For wiring I have a RS-232 cable (male to female) and a gender changer.

PC---gender changer------RS-232 cable---------data collector device

But it seems not work; the device is not receiving data. I assume that I may need a null modem cable. How can I solve this problem even without having a null modem cable? is there a software can change the wiring/pin assignment from PC side?

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You can get null modem adapters/cables for cheap these days, it's your best bet.

RS-232 ports are very much hardware-centric. You'd have better luck rewiring the pins on the motherboard than trying to find a motherboard that allows BIOS-level pin reassignment, let alone software-level.

You could possibly hack and rewire your serial cable into a null modem cable. Pin-out information is available here (amongst many other places). I wouldn't trust doing this, due to signal interference.

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No. You will need a null modem cable. This cannot be done with software.

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Hit your local electronic parts house and get a null-modem adapter. Replace the gender bender with the adapter and you should be set.

If you have a Radio Shack nearby, they carry them for about $13.00.

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