Serial Cable Pinout for Olympus D-400Z Digital Camera

This cable has a normal PC 9-pin D-sub female serial connector (DB-9) at one end and a standard 2.5 mm stereo audio stereo plug (male) at the other end. Only three signal wires are needed in the cable: ground (Gnd), transmit data (TxD) and receive data (RxD). Depending up what software you use, you also may need to "loop-back" data terminal ready (DTR) to data set ready (DSR) and request to send (RTS) to clear to send (CTS) on the DB-9 connector.

The stereo plug is wired to the PC serial port as shown in the following diagram:

         tip   ring     sleeve     +---------------------------------+
                                   |                                 |
      /-------+-----+--------------+                                 |
     |   RxD  | Gnd |     TxD      |      2.5 mm Stero Plug          |
      \-------+-----+--------------+                                 |
                                   |                                 |
  DB9*: pin 2  pin 5    pin 3      +---------------------------------+

  DB9*: Optionally short together pin 4 (DTR) to pin 6 (DSR) and 
        pin 7 (RTS) to pin 8 (CTS)
The following table also describes the camera cable's wiring:
   Camera    PC's
    Plug     DB9*     Signal Name                Direction
    ----     ----     -----------                ---------
      -       1       Carrier detect (CD)        input to PC
     tip      2       Receive data (RxD)         input to PC
    sleeve    3       Transmit data (TxD)        output from PC
      -       4 \     Data terminal ready (DTR)  output from PC
     ring     5  |    Signal ground (Gnd)        -
      -       6 /     Data set ready (DSR)       input to PC
      -       7 \     Request to send (RTS)      output from PC
      -       8 /     Clear to send (CTS)        input to PC
      -       9       Ring indicator (RI)        input to PC
* Note that the cable's D-subminature DB9 RS-232 serial port connector is female. This connector also goes by the historically more correct name of "DE-9J".

If you are using this cable with the "freeware" from "photopc", then you don't need to "loop-back" wires on pins 4/6 and pins 7/8 of the DB9 connector. However, these wires may be needed for the "official" Olympus Windows software.

Hint: The parts for this cable can be purchased at most any electronics parts store, such as Radio Shack. One option is to buy an audio "patch cable" with a 2.5 mm stereo plug molded onto one end, then cut off the other end and then wire it to pins 2, 3 and 5 of a DB-9 female connector. A quick continuity check with something like a digital volt meter (DVM) will tell you which wires go to which contacts on the stereo plug. All of the DB-9 connectors that I have come across have tiny pin numbers by the contacts to aid you.

Radio Shack sells a number of "flavors" of 2.5 mm stereo plugs, pre-wired patch cables and DB-9 connectors. It is even possible to avoid using a soldering iron for this by using a pre-wired patch cord and a DB-9 connector "kit" with "crimp-style" push-in pins.

To help make the "electrically inept" a bit braver about making their own camera cable, I wouldn't worry too much about possibly getting the wiring wrong at first and damaging something. PC serial ports use RS-232 signaling, which is electrically "robust" in that the inputs and outputs are protected against short circuits and unusual voltages. In my 30+ years of abusing RS232 serial port wiring, I have yet to damage a serial port. (However, you are on your own!)

Bruce D. Lightner, last updated Fri May 2 11:57:14 PDT 2003 .