Giga-tronics 58542 - Channel Configuration Examples; Single Sensor Power Measurement; Ratio Measurement; Difference Measurement

58542 VXIbus Universal Power Meter
A-28 Publication 21555, Rev. E, September 2002
A.6 Channel Configuration Examples
A.6.1 Single Sensor Power Measurement
Default definition of software calculation channels 1 and 2 are for sensors 1 and 2, respectively. This
configuration allows measurement of the power level incident upon sensor 1 on software configuration
channel 1, and measurement of the power level incident upon sensor 2 on software configuration
channel 2. Normal Mode and Swift Mode measurements are faster with only one sensor set to STATe
ON. Since this is the default configuration, consider turning one channel off occasionally. This will only
be necessary when two sensors are attached and both are calibrated. Channel configuration can be
changed by sending the CALCulate:RATio or CALCulate:DIFFerence commands.
OUTPUT @Pwr_mtr;*RST ! Configure 58542 to Default Setup
OUTPUT @Pwr_mtr;CALC1?;CALC2? ! Query channel configuration
ENTER @Pwr_mtr;Chn1_config,Chn2_config
PRINT Chn1_config,Chn2_config
Program Output: POW 1 POW 2
The following program reverses the default sensor-to-channel assignments.
OUTPUT @Pwr_mtr;CALC2:POW 1 ! Configures channel 2 to measure Sensor 1 power
OUTPUT @Pwr_mtr;CALC1:POW 2 ! Configures channel 1 to measure Sensor 2 power
OUTPUT @Pwr_mtr;CALC1?;CALC2? ! Query channel configuration
ENTER @Pwr_mtr;Chn1_config,Chn2_config
PRINT Chn1_config,Chn2_config
Program Output: POW 2 POW 1
A.6.2 Ratio Measurement
The CALCulate:RATio command is used to automatically measure the ratio of the power levels
incident on the two sensors. Permissible settings are Sensor 1/Sensor 2 & Sensor 2/Sensor 1.
OUTPUT @Pwr_mtr;CALC1:RAT 2,1 ! Configures channel 1 to measure Sensor 2 over
! Sensor 1 power
OUTPUT @Pwr_mtr;CALC2:RAT 1,2 ! Configures channel 2 to measure Sensor 1 over
! Sensor 2 power
OUTPUT @Pwr_mtr;CALC1?;CALC2? ! Query channel configuration
ENTER @Pwr_mtr;Chn1_config,Chn2_config
PRINT Chn1_config,Chn2_config
Program Output: RAT2,1 RAT1,2
A.6.3 Difference Measurement
The CALCulate:DIFFerence command is used to automatically measure the difference of the power
levels incident upon the two sensors.
OUTPUT @Pwr_mtr;CALC1:DIFF 2,1 ! Configures channel 1 to measure Sensor 2 minus
! Sensor 1 power
OUTPUT @Pwr_mtr;CALC1? ! Query Channel 1 configuration
ENTER @Pwr_mtr;Chn1_config
PRINT Chn1_config
Program Output: DIFF2,1