
Teledyne API Model 300M CO Analyzer Instruction Manual, 04033, Rev. A
3.Adapters - these change from one type plug
4.Null modems - here the connector changes the internal wiring so that DTE devices can become DCE or vice versa. The main internal change is swapping pin 2 and
3so that data is transmitted and received on opposite pins.
NOTE
NULL MODEMS CAN ALSO COMBINE GENDER CHANGER OR ADAPTER FEATURES IN THE DESIGN. WHEN MAKING UP AN ADAPTER CABLE BE CAREFUL TO NOTE WHAT YOU ARE USING, ESPECIALLY WITH COMBINATION NULL
Wiring:
The
a printer to the instrument that is likewise wired as a printer. To help understand the different problems - 3 examples as shown below:
Example 1: Connecting the Teledyne API analyzer to an
In this case the PC is wired as DCE and the analyzer is wired as DTE therefore a null modem is not needed. The wiring is "straight through" i.e. pin 1 to pin 1, pin 2 to pin 2, etc. Therefore all you have to do here is adapt the connector on the analyzer (male
Example 2: Connecting the Teledyne API analyzer to a serial printer.
In this case both the analyzer and the printer are wired as DTE so a "Null Modem" will have to be inserted in the line to change the wiring to make the analyzer look like a modem (i.e. DCE). Make sure in using your adapters that ONLY ONE null modem connector is used. Null modems can be purchased in
Example 3: Connecting the Teledyne API analyzer to a modem.