Zero-modem cable is used for a cross-over serial connection (RS232) between 2 DTEs (computer, terminal, printer, etc.). The name derives from the use of RS232 cables to connect two teleprinter units to two modems to communicate with each other. DTE and the other is a DCE. With a zero modem connection, the transmission and receive lines are cross-linked. Depending on the purpose, sometimes one or more handshake compounds are also...

Zero-modem cable is used for a cross-over serial connection (RS232) between 2 DTEs (computer, terminal, printer, etc.). The name derives from the use of RS232 cables to connect two teleprinter units to two modems to communicate with each other. DTE and the other is a DCE. With a zero modem connection, the transmission and receive lines are cross-linked. Depending on the purpose, sometimes one or more handshake compounds are also cross-linked. Several wiring layouts exist, since a null modem connection is not covered by the RS232 standard.