Giga-tronics 58542 - High Speed Measurements; Operating Mode Control

58542 VXIbus Universal Power Meter
2-30 Publication 21555, Rev. E, September 2002
2.5.18 High Speed Measurements
■ CALCulate:DATA?
■ CALCulate:MODE
■ TRIGger:MODE
■ TRIGger:DELay
■ TRIGger:COUNt
Measurements in Normal mode are fastest with only one sensor attached. When two sensors are
attached, the Normal mode measurement rate is reduced. This applies for all three major measurement
commands, FETCh, READ and MEASure. Both of the averaging types, MOVing and REPeat, slow
down when in the Normal mode. MOVing provides faster averaging; the speed is equivalent to REPeat
whenever the Averaging number is 1.
When performing measurements in either Swift or Burst modes, measurement rates are the same with
two sensors as with one sensor. Approximate measuring speeds are listed in Table 2-3.
2.5.18.1 Operating Mode Control
The Operating mode is controlled through the CALC#:MODE command. The choices are NORMal,
BURSt and SWIFt. Sending CALC1:MODE will set the operating mode for the entire instrument, not
just for channel 1. The fast mode permits more frequent return of measurement data to the host during
operation in the modulated measurement modes (MAP, PAP or BAP).
CALC:DATA?
Syntax:
CALCulate<channel 1 to 2>:DATA?
Example:
OUTPUT @PWR_MTR;CALC1:DATA? ! QUERIES CHANNEL 1 & 2 BURST MODE DATA
Description:
This command interrupts the burst measurement and dumps the measurement buffer. All
empty locations will be filled with -300 before the data dump. The Burst mode remains active
after this command so that a trigger will start a new measurement reference.
The command returns measurement data (while the measurement is completing) during
BURSt mode only. This command is not used in NORMal or SWIFt Modes. Operation is
similar to using FETCh? Both are instrument (not channel) commands. That is, when both
sensors are connected, calibrated, and the channel set to ON, this command will return power
level data for both channels.
CALC:MODE
Syntax:
CALCulate<channel 1 to 2>:MODE space<NORMal, BURSt or SWIFt selection>
Example:
OUTPUT @PWR_MTR;CALC2:MODE NORMAL ! SETS THE MEASUREMENT TO NORMAL
Description:
This command sets the measurement mode. This is NOT a channel-specific command; it is
an instrument configuration command. Selecting one channel changes both channels to the
desired mode. Use this command to select the level of functionality and performance for
unique applications. NORMal Mode is full functioned. SWIFt Mode allows individual data
point triggering. BURSt Mode allows the fastest measurement rates.