I have a scientific instrument that uses a DB9 cable to connect to the standard RS232 port on a computer for communication. I've deconstructed one of the cables as I needed to make another one but I am wondering if this wiring pattern is a standard wiring variation seen with DB9 cables or if it is completely proprietary. I don't want to have to make these cables if I don't have to.

DB9 Wiring Diagram

  • \$\begingroup\$ Questions seeking recommendations for products get closed here. Can I suggest that you reword your question to ask for a solution to the problem rather than a recommendation for a product. \$\endgroup\$ – RoyC Oct 28 '18 at 8:33
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    \$\begingroup\$ It's more about identifying this particular pinout than about where to buy it. \$\endgroup\$ – Dmitry Grigoryev Oct 30 '18 at 8:32

That is a standard null modem cable with handshake also known as crossover.

It is used to connect two DCE devices or two DTE devices together.

DCE (data circuit-terminating equipment) .... example: modem
DTE (data terminal equipment) .................... example: computer

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TXD - transmit data
RXD - receive data
RTS - request to send   
CTS - clear to send
DTR - data terminal ready
DSR - data set ready
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    \$\begingroup\$ With both DTR/DSR and CTS/RTS handshake. There are cables without one or the other handshake in the wild. \$\endgroup\$ – Janka Oct 26 '18 at 22:40
  • \$\begingroup\$ Thank god I don't have to make any more. \$\endgroup\$ – test Oct 26 '18 at 22:52

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