VNA Master™Programming Manual : Vector Voltmeter Commands : :TRACe VVM Subsystem
 
:TRACe VVM Subsystem
This subsystem contains commands pertaining to the Vector Voltmeter mode.
:TRACe VVM Subsystem Commands 
Keyword
Parameter Form
Parameter Data or Units
Notes
:TRACe
 
 
 
:PREamble?
<char>
Returns block data
Query Only
 
Trace Header Transfer
:TRACe:PREamble?
Description
Query only. Returns trace header information. The response begins with an ASCII header. The header specifies the number of following bytes. It appears in the format #AX, where A is the number of digits in X, and X is the number of bytes that follow the header.
Parameters are returned in comma‑delimited ASCII format. Each parameter is returned as “NAME=VALUE[UNITS]”. Note that the parameters that are returned depend on the firmware version and that this document does not cover all parameter values that are returned by the command. Refer to Table: Trace Header Parameters  (Sheet 1 of 2).
For the example response, the serial number (SN) is 83320012 and is returned as “SN=83320012”. Refer to section Example Response Format:.
Syntax
:TRACe:PREamble?
Query Response
<char> (returns block data)
Front Panel Access
NA
 
Example Response Format:
[#800001070SN=83320012,UNIT_NAME=,TYPE=DATA,DATE=1999-11-30-02-00-10-10,
APP_NAME=MWVNA,APP_VER=T0.00.1001,VVM_MODE=0.000000,VVM_CW_FREQ=
0.005000,VVM_MEAS_TYPE=0.000000,VVM_RETURN_MEAS_FORMAT=0.000000,
VVM_CABLE=1.000000,VVM_PORT_1_SAVE_RETURN_REF=0.000000,VVM_PORT_1_
SAVE_INSERTION_REF=0.000000,VVM_PORT_2_SAVE_RETURN_REF=0.000000,VVM_PORT_2_SAVE_INSERTION_REF=0.000000,VVM_PORT_1_RETURN_REF_AMP=
0.000000,VVM_PORT_1_RETURN_REF_PHASE=0.000000,VVM_PORT_1_RETURN_REF_VSWR=1000.000000,VVM_PORT_1_RETURN_REF_REAL=0.000000,VVM_PORT_1_
RETURN_REF_IMAG=0.000000,VVM_PORT_1_INSERTION_REF_AMP=0.000000,VVM_
PORT_1_INSERTION_REF_PHASE=0.000000,VVM_PORT_1_RETURN_REF_RAW_
REAL=1000000.000000,VVM_PORT_1_RETURN_REF_RAW_IMAG=0.000000,VVM_PORT_2_RETURN_REF_AMP=0.000000,VVM_PORT_2_RETURN_REF_PHASE=0.000000,VVM_PORT_2_RETURN_REF_VSWR=1000.000000,VVM_PORT_2_RETURN_REF_REAL=
0.000000,VVM_PORT_2_RETURN_REF_IMAG=0.000000,VVM_PORT_2_INSERTION_
REF_AMP=0.000000,VVM_PORT_2_INSERTION_REF_PHASE=0.000000,VVM_PORT_2_
RETURN_REF_RAW_REAL=1000000.000000, VVM_PORT_2_RETURN_REF_RAW_IMAG=0.000000, CAL_PORT=1]
Trace Header Parameters
Table: Trace Header Parameters  (Sheet 1 of 2) describes parameters that can be returned by the :TRACe:PREamble? command.
Trace Header Parameters  (Sheet 1 of 2)
Parameter Name
Description
SN
Instrument Serial #
UNIT_NAME
Instrument name
DATE
Trace date/time
APP_NAME
Application name
APP_VER
Application firmware (FW) version
VVM_MODE
Mode
0 = CW
1 = Table
VVM_CW_FREQ
CW frequency
VVM_MEAS_TYPE
Measurement Type
0 = Return
1 = Insertion
VVM_RETURN_MEAS_FORMAT
Return Type Measurement Format
0 = dB
1 = VSWR
2 = Impedance
VVM_CABLE
Selected Cable number 1 to 12
VVM_PORT_X_SAVE_RETURN_REF
Saved status for Port x Return reference,
where x = 1 or 2
VVM_PORT_X_SAVE_INSERTION_REF
Saved status for Port x Insertion reference,
where x = 1 or 2
VVM_PORT_X_RETURN_REF_AMP
Return reference amplitude for Port x,
where x = 1 or 2
VVM_PORT_X_RETURN_REF_PHASE
Return reference phase for Port x,
where x = 1 or 2
VVM_PORT_X_RETURN_REF_VSWR
Return reference VSWR for Port x,
where x = 1 or 2
VVM_PORT_X_RETURN_REF_REAL
Return reference real for Port x,
where x = 1 or 2
VVM_PORT_X_RETURN_REF_IMAG
Return reference imaginary for Port x,
where x = 1 or 2
VVM_PORT_X_INSERTION_REF_AMP
Insertion reference amplitude for Port x,
where x = 1 or 2
VVM_PORT_X_INSERTION_REF_PHASE
Insertion reference phase for Port x,
where x = 1 or 2