Boonton 4530 Peak Power Meter User Manual - Manual (Page 111)

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Boonton Electronics Chapter 4
4530 Series RF Power Meter Remote Operation
4.5.12 SENSe:MBUF Data Array Commands
The MBUF commands (which are grouped under the SENSe subsystem) are used to control buffered data capture and
output of a long array of sequential readings (the “Measurement BUFfer”). This capability is useful for capturing
readings at a rate higher than the host system can read back in real time. These commands are used in all but Statistical
modes, and allow control of buffer size, reading rate, status reporting, and buffer array output. Up to 4,096 readings
may be captured at programmable rates up to 1000 readings per second in Modulated or CW mode, and up to 500
triggered readings per second in Pulse Mode (timespan dependent). In Modulated and CW mode, each stored reading
in the measurement buffer is the value that would be returned as the current average power measurement over the
GPIB, including all filtering. To ensure no overlap between measurements, it may be preferable to set filtering off, or to
a value shorter than the buffer period, which is the inverse of the
SENSe:MBUF:RATe setting. In Pulse mode, each
stored reading in the measurement buffer is the value that would be returned as the “average power between markers”
over the GPIB, including all averaging. To ensure no overlap between measurements,
SENSe:AVERage should be
set to 1, and DISPlay:TSPAN should be set to 50 microseconds or slower. If it is important that the average power over
every pulse be recorded, sufficient time after the trigger must be allowed for the power meter to complete the sweep, and
rearm for the next sweep. Typically, this time is 3ms longer than the current timespan setting, assuming the trigger edge
is kept close to the left edge of the screen. For example, on a 10ms timespan, the pulse repetition frequency should not
exceed 80 Hz (1 / 10 + 3ms), or some pulses may be missed.
SENSe:MBUF:SIZe
Description: Set or return the size of the measurement buffer. This controls how many readings will be
buffered before the buffer is considered full. If set to zero, the measurement buffer is
disabled, and the instrument operates in normal mode. If
INITiate:CONTinuous is OFF ,
measurements will be considered complete, and the instrument will stop when the buffer
has filled. Time to fill the buffer is determined by SIZE divided by RATE in Modulated and
CW modes (see below), and by the trigger rate in Pulse mode.
Syntax: SENSe[1|2]:MBUF:SIZe <n>
Argument: <n> = 0 to 4096 (0 = Buffered Measurements disabled)
Valid Modes: Modulated, CW or Pulse modes
SENSe:MBUF:RATe
Description: Set or return the reading acquisition rate for the measurement buffer in Modulated and CW
modes. This controls how fast readings are placed into the measurement buffer, and SIZE
divided by RATE determines how many seconds it will take to fill the buffer. Note that
buffer readings may be repeated if RATE is set faster than the internal measurement rate of
the instrument (500 readings/sec in Modulated mode, 300 readings/second in CW mode),
and best performance is achieved when RATE equals, or is an exact submultiple of the
internal measurement rate. Note that this command has no effect on Pulse mode buffering.
Syntax: SENSe[1|2]:MBUF:RATe <n>
Argument: <n> = 1 to 1000 buffered readings/second
Valid Modes: Modulated and CW modes