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RS232 - DB9 to RJ45 adapter pinout 1

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salmans

salmans

Computer
Apr 17, 2003
4
I am trying to connect a General Electric PQM (Power Quality Meter) to a PC. I had it connected to a laptop via DB9 null modem cable, and it was working fine, but needed to run it permanently to a PC. I have two DB-9 to RJ-45 adapter's, the female is at the PC and the male at the PQM. There are only a few hundred pinouts for this on the internet but I havent had any luck finding anything that works. I know it should be simple and for most of you I'm sure it is but I am running out of hair to pull out and could use some assistance. I just need the pinout for the two DB9 to RJ45 adapters and should I use a straight through RJ-45 cable or crossover, but I guess it depends on if the wires cross in the adapters. Please anyone....HELP!!!
 
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This always works for me.

If the connection is a straight through, (as in a modem cable type connection):

Both DB9 adapters are to be configured as follows- the yellow wire is inserted into pin 2, the black wire is inserted into pin three, the red wire is inserted into pin 5. The connector on the GE PQM side should have pins 4&5 (RTS/CTS) shorted, (if required). If the adapter does not come with a separate shorting jumper wire, you can cut some of the excess wires off and solder a jumper together. This will allow you to use a standard ethernet cable (straight through), even if it is only configured with four wires.

If the connection requires a null modem connection, reverse the yellow and black wires on one of the connectors.

If you require handshaking between the PC and PQM, use any two unused pairs in the connectors, inserted in pins 4 & 5, and swap the colors on one connector.

I hope this helps.
 
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It's up and running like a champ...Thanks robertjo24 !!!
I was trying to overcomplicate the situation the whole time. Thanks again!
 
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