Sense[N]:Power:reference:state:ratio; Sense[N]:Power:unit[:All] - Keysight N774 C Series Programming Manual

If you want to reference another power sensor channel, use an integer value corresponding to the slot for the first parameter
and an integer value corresponding to the channel for the second value.
If you want to use an absolute reference, use TOREF as the first parameter and any integer value as the second parameter.
Response: None
Example: :ens1:pow:ref:stat:rat 2,1
:sens1:pow:ref:stat:rat TOREF,1
Affects All power meters
Command:

:SENSe[n]:POWer:REFerence:STATe:RATio?

Syntax: :SENSe[n]:POWer:REFerence:STATe:RATio?
Description: Returns the reference setting for the channel.
Parameters: None
Response: Results are displayed relative to an absolute reference or to the current power reading from another channel.
Example: :sens1:pow:ref:stat:rat? → +255,+0
:sens1:pow:ref:stat:rat? → +2,+1
Affects All power meters
Command:

:SENSe[n]:POWer:UNIT[:ALL]

Syntax: :SENSe[n]:POWer:UNIT<wsp>DBM|0|Watt|1
Description: Sets the sensor power unit of selected channel or of ALL channels.
Parameters: An integer value:
or DBM or Watt
Response: None
Example: :sens1:pow:unit 1
:sens:pow:unit:all 1
Affects All power meters
Keysight N774xC Series Multiport Power Meter Programming Guide
Measurement Operations & Settings
References channel 2.1
References an absolute reference
results are displayed relative to an absolute reference
results are displayed relative to channel 2.1
0: dBm
1: Watt
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