This read-write INTEGER, on write, turns off this control board's power supply, while a read always returns off; the description notes control boards otherwise power on automatically upon insertion or when housekeeping power is applied, so this object only ever supports commanding power off, not on. An administrator uses this specifically to power down a control board deliberately, for instance before physically removing it. For example, writing to this object before extracting a standby control board avoids a live power removal of that unit.