I laid my hands on a old power supply (Cisco ADP-29DB CC:B1/1, it came with an Cisco ISDN router many moons ago) and it has a connector with the following pinout:

\begin{array}{ccc} \text{-12V / 100mA}&*&*&\text{-24V / 120mA}\\ \text{+12V / 100mA}&*&*&\text{-71V / 120mA}\\ \text{RTN}&*&*&\text{RTN}\\ \text{ROF}&.&*&\text{+5V / 120mA}\\ \end{array}

Most pins are clear, I guess 'RTN' is simply short for 'return' or GND. Which leaves one pin with an unclear marking:

What does ROF mean? An interesting detail is that the pin for ROF is a bit deeper down into the connector so it makes contact last of all pins, implying that is has something to do with hot-plugging the PSU.


ROF stands for Remote On/Off. This pin must be grounded for the supply to work.

  • \$\begingroup\$ What is it used for? \$\endgroup\$
    – VanGo
    Jan 4 '18 at 11:18

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