All RS232 devices that use a DB-9 connector should conform to the standard TIA/EIA-574. The device should be either DCE or DTE. DCE devices should have a female DB-9 connector, and DTE devices should have a male DB-9 connector. For a description of pin outs for the RS232 DB-9 connector see attached document "PinoutStndrds.pdf" from Cisco (page 2). Any RS232 device that has a DB-9 connector and conforms to this standard will connect easily to the Digi PKG-R (PKGR) or development kit radio modems.
These guidelines can help in understanding the terminology:
- RS232 COM ports are normally configured as either a DTE (Data Terminal Equipment) port or a DCE (Data Communications Equipment) port.
- The COM port on a personal computer is a DTE port (male).
- The COM port on Digi radio modems are configured as DCE port (female).
- Any device that connects to a computer COM port using a straight through serial cable is a DCE device.
- Connect a DCE device to another DCE device using a null modem (male-to-male) adaptor.
- Connect a DTE device to another DTE device using a null modem (female-to-female) adaptor.
- Replace a straight through serial cable with RF modems according to the diagram below:
Find more information and detailed RS232 connection drawings in the PKG-R product manual.