Measurement function of the KFM2150 | Simple measurement procedure (MEASure)
Measurement procedure with flexibility (READ) | Most flexible measurement procedure (INITiate and FETCh)
Measurement using software triggers | Multipoint measurement with specified trigger count
Waveform data retrieval function

Multipoint measurement with specified trigger count

The KFM2150 allows up to 16 measurement operations to be carried out with a single start action (READ? or INIT). The number of measurements is specified by the trigger count.

Once the measurement is started with READ[:<meter_fn>]? or INIT, the KFM2150 continuously measures the number of times specified in advance by the trigger count. When all measurements are complete, the measured data can be retrieved. If the trigger source is set to IMM (immediate, default), the specified number of measurements proceeds automatically after the READ? or INIT command. If the trigger source is set to BUS, software triggers (*TRG command or the IEEE488.1 get message) must be sent the specified number of trigger counts after INIT. If the trigger source is set to TIM, measurement is performed after a lapse of the specified time by TRIG:TIM after INIT. The specified time is in units of seconds [s], and the maximum value is 60 s.

Example:

TRIG:SEQ1:COUN 4

 
TRIG:SEQ1:TIM 1.0  
TRIG:SEQ1:SOUR TIM  

INIT;*OPC?

 
(Read the response)
FETC:IMP? 'Query the impedance data (magnitude) that has been measured.
(Read the response)
FETC:IMP:RES?;REAC?;PHAS? 'Query the resistance, reactance, and phase data.
(Read the response)

When all the measurements specified by the trigger count are complete, the response (ASCII character “1”) to *OPC? can be retrieved. Then, the data can be retrieved using FETC[:<meter_fn>]?.

The second level node of FETC?, READ?, and MEAS? can be [SCALar] or ARRay. [SCAL] is a default node designation that can be omitted. It returns a single value regardless of the trigger count designation. The response to FETC[:<meter_fn>]? is the result obtained by averaging all the specified number of counts of data. However, if invalid data such as over range exists in the values of the multipoint measurement, such data is excluded from the averaging process. If the data of all counts are invalid, invalid data (SCPI INF = 9.9E37 for over range and SCPI NINF = -9.9E37 for under range) is returned as the average data as an exception.

ARR can be specified in place SCAL. When ARR is specified, multiple points of measured data separated by commas are returned according to the trigger count designation. Table 6 indicates the contents of the response when [SCAL] and ARR are specified for the trigger count designation.

Example:

FETC:ARR:IMP?

  'Query the impedance data (magnitude) that has been measured in an array.
(Read the response)  
FETC:ARR:IMP:RES?   'Query the impedance data (resistance) that has been measured in an array.

(Read the response)

 
FETC:ARR:IMP:REAC? 'Query the impedance data (reactance) that has been measured in an array.
(Read the response)
FETC:ARR:IMP:PHAS? 'Query the impedance data (phase angle) that has been measured in an array.
(Read the response)
READ:ARR:VOLT? 'Start the voltage measurement and query the data in an array.
(Read the response)
FETC:ARR:CURR? 'Query the current data that was measured simultaneously with the voltage measurement in an array.
(Read the response)