Keysight Technologies 3458A Guide D'utilisation page 165

Making Measurements 4
High-speed transfer from memory
Configuring the reading memory format (MFORMAT command) to match the
output format (OFORMAT command) helps to ensure command) to match the
fastest transfer of readings from reading memory to the controller. This is because
no conversion is necessary when the readings are recalled from memory. For
high-speed, low resolution readings (3.5 or 4.5 digits) made on a fixed range, use
the SINT format. (Because the SINT format uses only 2 bytes per reading, multiple
readings can be stored in memory and transferred across the bus faster using the
SINT output format than any other format.) For the fastest transfer of high
resolution readings (5.5 digits or greater) made on a fixed range, use the DINT
format. Whenever autorange is enabled and transfer speed is critical, use the
SREAL format (for readings of 6.5 digits or less) or the DREAL format (for readings
of 7.5 or 8.5 digits). Disabling the display and any math operations will also
ensure the fastest transfer from reading memory to the controller.
The following program is an example of transferring readings from reading
memory to the controller at the fastest possible rate. The program stores 5000
readings in reading memory using the SINT format. The readings are removed
from memory using the "implied read" and transferred to the controller (in the
SINT format) using the TRANSFER statement (line 130). The controller then
retrieves the scale factor, multiplies the scale factor times each reading, and
stores the corrected readings in the Rdgs array.
10 OPTION BASE 1!COMPUTER ARRAY NUMBERING STARTS AT 1
20 INTEGER Num_readings!DECLARE VARIABLE
30 INTEGER Int_rdgs(1:30000) BUFFER!CREATE INTEGER ARRAY FOR BUFFER
40 REAL Rdgs(1:30000)!CREATE REAL ARRAY
50 Num_readings=30000!NUMBER OF READINGS = 30000
60 ASSIGN @Dvm TO 722!ASSIGN MULTIMETER ADDRESS
70 ASSIGN Int_rdgs TO BUFFER Int_rdgs(*)!ASSIGN BUFFER I/O PATH NAME
80 OUTPUT @Dvm; "PRESET FAST"!TARM SYN,TRIG AUTO, DCV 10 V
90 OUTPUT @Dvm;"APER 1.4E-6"!1.4 µs INTEGRATION TIME
100 OUTPUT @Dvm; "OFORMAT SINT"!SINT OUTPUT FORMAT
110 OUTPUT @Dvm; "NRDGS"; Num_readings !30000 READINGS/TRIGGER, AUTO
115 !SAMPLE EVENT (DEFAULT VALUE)
120 TRANSFER @Dvm TO @Int rdgs;WAIT!SYN EVENT, TRANSFER READINGS INTO
121 !INTEGER ARRAY; SINCE THE COMPUTER'S INTEGER FORMAT IS THE SAME AS
125 !SINT,NO DATA CONVERSION IS NECESSARY HERE (INTEGER ARRAY REQUIRED)
130 OUTPUT @Dvm; "ISCALE?"!QUERY SCALE FACTOR FOR SINT FORMAT
140 ENTER @Dvm;S!ENTER SCALE FACTOR
150 FOR I=1 TO Num_readings
Keysight 3458A User's Guide 165