DB-25 4-Wire Hardware Handshaking (Ready/Busy) Cable

The following four-wire cable is often sufficient for a terminal, printer, or other DTE device configured for DTR (hardware) flow control. However, some terminals and printers may use a signal other than DTR for flow control. In addition, some terminals and printers may have other cable requirements. Consult your terminal or printer manual for this information. For more universal compatibility, use a fully-wired DB-25 terminal/printer cable.

Terminal/Printer Cable with DTR Handshaking
DB-25 Female
(Digi End)
  DB-25 Male
(Peripheral)
Signal Pin Pin Signal
TxD 2 connected to 3 RxD
RxD 3 connected to 2 TxD
CTS 5 connected to 20 DTR
SG 7 connected to 7 SG
GND Shell connected (via shield) to Shell GND
  jumpered 4 & 5 RTS & CTS
  

Note: Some Okidata printers use a control signal on pin 11, called Supervisory Send Data (SSD) instead of DTR. In this case, simply connect CTS on the female DB-25 side to pin 11 of the male DB-25, instead of pin 20.