RAD console cable (25 pin)

Wiring for the RAD Data Communications console cable using two DB-25 female connectors, used to configure devices such as the FPS-8 switch via EIA-232.

The RAD console cable connects a PC serial port to the management port of RAD Data Communications equipment such as the FPS-8 packet switch. Both ends use 25-pin D-sub female (DB-25F) connectors wired as a null-modem crossover, carrying EIA-232 signals between the PC (DTE) and the device. The cable supports the standard console session signals: transmit data, receive data, hardware handshake lines, and signal ground.

25 pin D-SUB female connector layout 25 pin D-SUB female connector to the computer

25 pin D-SUB female connector diagram 25 pin D-SUB female connector to the device

PC Pin namePC PinDirectionRAD switch PinRAD switch Pin nameDescription
TxD2OUT6
RxD3IN5
RTS4OUT8
CTS5IN7
DSR6IN1May be shorted with DCD
GND7-4
DCD8IN2May be skipped if shorted with DSR in DB-25
DTR20OUT3

Notes

Both connectors are DB-25 female; the cable is a null-modem crossover with TxD/RxD and the handshake lines (RTS/CTS, DTR/DSR/DCD) transposed between PC and device sides. DCD on the PC side (pin 8) may be omitted if DSR and DCD are shorted together at the DB-25 connector on the device side. RAD switch pin signal names are not publicly documented by the manufacturer.

Signals

  • TxD — Transmit Data; PC sends serial data to the RAD device
  • RxD — Receive Data; PC receives serial data from the RAD device
  • RTS — Request To Send; PC asserts readiness to transmit
  • CTS — Clear To Send; RAD device signals readiness to receive
  • DSR — Data Set Ready; RAD device asserts active state; may be shorted with DCD on the device connector
  • GND — Signal ground
  • DCD — Data Carrier Detect; may be skipped if shorted with DSR in the DB-25 connector on the device side
  • DTR — Data Terminal Ready; PC asserts readiness

References

  • TIA/EIA-232-F — Interface Between Data Terminal Equipment and Data Circuit-Terminating Equipment Employing Serial Binary Data Interchange (Telecommunications Industry Association); DB-25 null-modem console wiring.

Category:Miscellaneous Cables