Keysight EL30000 Serie Guide D'utilisation page 87

Operation
Once configured and enabled, turning the load input on or off on any coupled input will cause all coupled inputs on
all configured loads to turn on or off according to their user-programmed delays. This applies to the front panel On
and Off keys, the Web server, and to SCPI commands.
Turning the load inputs on or off using the front panel [All On/Off] key will cause all coupled inputs as well as non-
coupled inputs on that load to turn on or off.
Keysight EL30000 Series User's Guide 87