Dsub 9 pin M/M adaptor need to swap TX/RX

Okay experts, here is one I need help with.

We have Omron touchscreens for some of our equipment. We can't get the older ones anymore, so we have to get new ones. No biggie right?

The RS232 from the PLC to the touchscreen pinouts are different. The TX/RX are swapped.

Sooo, what I have tried to find is a 9 pin M/M D-sub patch connector where I an put the wires in the patch connector as needed. I can't rewire the connector itself in case we have to slap an old style screen back in. We have some larger ones that we use to add some HF filter caps, 30 pin I think, like the ol' parellel printer cable, PC side. So I know they are made. I can connect pins 2 to 3 and 3 to 4 etc as I see fit.

Problem is, on Digikey, Newark, and Mouser, for the life of me I can't find it.

Ideas, links would be appreciated.

You need a Serial Null Modem cable. That's the official name. You'd have to swap cables when you use something that needs a straight through thing of course.
I've seen patch connectors in the past, I'll see if I can find one.

EDIT:
You may have to use a 9pin to 25pin serial converter, a 25pin patch connector, and then a second 25pin to 9pin converter.
Clunky, but it'd work at least.

2.EDIT:
How about null modem adapters permanently attached to the screens that want TX/RX swapped? That'd convert them to match the others.
http://www.ebay.com/itm/YourCableSt...A%2BFICS%2BUFI&otn=21&pmod=380464811505&ps=54

So it swaps the rx/tx pins?
Perfect and space is limited.
Thanks!

Yup, the null modem thing swaps TX and RX, otherwise it's straight through. The idea is to allow two computers to communicate with each other directly, without the use of modems and such.
Very, very old tech (like, pre-ethernet), I'm kind of surprised they're still available in large quantities!

Glad I could help!

Bobnova said:

Yup, the null modem thing swaps TX and RX, otherwise it's straight through. The idea is to allow two computers to communicate with each other directly, without the use of modems and such.
Very, very old tech (like, pre-ethernet), I'm kind of surprised they're still available in large quantities!

Glad I could help!

Click to expand...

I remember now. I had a few of the cables for xfering files back in the old days.