How Can I Identify DTE or DCE Type Connections?
What devices have DTE type RS-232 ports? A DTE device is "Data Terminal Equipment", this includes Computers, Serial Printers, PLC's, Video Cameras, Video Recorders, Video Editors, and most devices which are not used to extend communications. Think COMPUTER for DTE.
What devices have DCE type RS-232 ports? A DCE device is "Data Communications Equipment", this includes devices intended to plug directly into a DTE port, PDA cables, Modems and devices that extend communications like a modem, such as RS-422, RS-485, or Fiber Optic converters or Radio Modems. Think MODEM for DCE.
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Rule of Thumb: When connecting a DTE device to a DCE device, match the signal names. When connecting two DTE or two DCE devices together, use a crossover cable. (TD crosses to RD, RTS to CTS, DTR to DSR as shown in Modem to Modem connections)