HP 8530A Automated Measurements
This document introduces you to HP 8530A automated measurements.
Automated operation consists of two major categories:
Remote Programming
High Speed Operation
This is an introduction to controlling the receiver with a computer.
(Fast CW mode) This section explains how to acquire data at up to 5,000 points per
second using the 100,000 point data buffer. This material is written for programmers,
and contains programming examples.
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Contents
Remote Programming
High Speed Automated Operation (Fast CW and Fast IF Switching)
HP BASIC Fast CW Programming Examples
HP BASIC Fast IF Multiplexing Mode Programming Example
What is Remote Programming?
What this Section Explains
Transferable Data
Available Data Transfer Formats
CW Configuration
Multiple Frequency/Switch Control Configuration
What is Fast CW Mode?
Description of Fast CW Modes
Which Parameter is Measured in Fast CW Mode?
How to Transfer Fast CW Data
Facts about Overall Measurement Speed
Switch Speed
Frequency Switching Speed
Receiver Raw Data Acquisition Speed
Data Transfer Speed
Is Data Acquisition Synchronous with Data Transfer?
Transfer Speed Reduction Caused by Computer or HP-IB Extenders
Limitations
How Averaging Works with the Fast CW Buffer
Frequency Relationship Between RF and LO Source
Timing Considerations
Changing Minimum Re-Trigger Time
Standard Fast CW Mode
Fast Data Collection Mode
Autoranged Data Collection Mode
Fast IF Multiplexing
Using Fast IF Multiplexing Mode
Operating Notes and Driver Circuitry Requirements
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Remote Programming
What is Remote Programming?
"Remote programming" describes computer-controlled receiver operation. The receiver
can be ordered to make measurements, change settings, send data to the computer, or
accept data from the computer. Data that can be sent back and forth includes
measurement data, calibration coefficient sets, and so on. You can remotely use all front
panel features, and more.
Remote programming is often called "HP-IB operation" or "HP-IB programming."
Commands should be given in the same order as the equivalent front panel keystrokes.
What this Section Explains
This section briefly describes the main features of remote programming. "HP-IB
Programming" in the HP 8530A Operating and Programming Manual explains remote
programming in detail. The HP 8530A Keyword Dictionary lists all programming
(HP-IB) codes, and explains each command in detail.
Transferable Data
After making a measurement, you can send raw, corrected, or formatted measurement
data to the computer. These arrays represent different stages of data processing,
illustrated Figure 1. There are two entirely different, parallel, data processing paths. One
path is for Channel 1 and one is for Channel 2. Each channel has raw, corrected, and
formatted data arrays. In fact, you can modify the data using the computer, and send it
back into the array. The receiver will process the modified data through all following
stages.
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Figure 1. Data Processing Stages in the Receiver
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The following data arrays can be read by an external computer:
Table 1. Data Types
Raw Data
This data array contains the ratioed and averaged measurement data
results. (Note: In Fast CW mode, raw data is the only available format.) To
transfer the data from this array to the computer, use the HP-IB command
OUTPRAW
command sends data from the computer into the desired raw array. The raw
array data is in real,imaginary pairs. Refer to
Dictionary
commands mentioned below.
n
, where n is the desired parameter (1, 2, 3 or 4). The INPURAW
the HP 8530A the Keyword
for syntax and other information on this command, and the
n
Corrected
Data
Formatted
Data
Calibration
Coefficients
Delay Table
In addition to ratioing and averaging, corrected data has been through time
domain and calibration processing. Remember that these features must be
ON to affect the data. To transfer data from this array to the computer, use
the HP-IB command OUTPDATA
The INPUDATA
corrected data array. The corrected data array is in real,imaginary pairs.
This data is scalar (magnitude-only) and reflects display format, scaling, and
trace math processing. To transfer data from this array to the computer, use
the HP-IB command
The INPUFORM
corrected data array. Formatted data is a simple integer that represents the
data units shown on the display.
These are the error correction coefficients created during calibration (also
called a "Cal Set"). The error coefficient arrays can be read from, or sent to
a computer, just like the arrays described above. Refer to the descriptions
for the
OUTPCALC
Keyword Dictionary
Each parameter has its own special array called a "delay table." The table
can be retrieved by external computer, modified, then returned to the
receiver. The receiver will process the modified data as if it were actual
measured data. The table contains real/imaginary data pairs in the internal
Form 1 compressed format. A typical use is to modify frequency domain
data to synthesize a special window shape for use in time domain RCS
measurements. Refer to the descriptions for the OUTPDELA and INPUDELA
commands in the
n
command sends data from the computer into the desired
OUTPFORM
n
command sends data from the computer into the desired
and
INPUCALC
.
HP 8530A the Keyword Dictionary.
n
, where n is the desired parameter (1 to 4).
n
, where n is the desired parameter (1 to 4).
commands in the
HP 8530A the
Memory
Data
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Valid data can be read from this array
Refer to the descriptions for the OUTPMEMO command in the
Keyword Dictionary
memory from the computer. However, you can send data to the raw or
corrected array, then save it to memory using DATI)
. (There is no command to send data directly into a
if data has been stored to memory
HP 8530A the
.
Available Data Transfer Formats
In remote programming you can choose among four binary data formats, or one ASCII
data format. The formats are listed below:
Table 2. Available Data Transfer Formats
Form 1
This is the native internal data format of the receiver. Each point of data contains
a header byte, followed by three, 16-bit words. Form 1 offers very fast transfer
speeds, and Form 1 data can be converted to floating point data in the computer.
If you use Fast CW mode, the only data format available is Form 1. In fast CW
mode, Form 1 does not have the header information.
Form 2
Form 3
Form 4
Form 5
32-bit IEEE 728 format. This format is not commonly used.
This is the recommended format for use with HP 9000 Series 200/300
workstations. It consists of a header, a two-byte number indicating how many
bytes follow, then the real and imaginary data pairs for each stimulus point. Form
3 follows the 64-bit IEEE 728 standard format.
This format is ASCII.
This is the recommended format for use with IBM PCs and compatibles. This is a
32-bit DOS-compatible floating point format.
Refer to the Keyword Dictionary under “Form1,” “Form2,” “Form3,” “Form4,” or
“Form5” for more detailed information.
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High Speed Automated Operation
Fast CW mode is a feature that optimizes HP 8530A data acquisition speed. There are
two major system configurations that use Fast CW modes:
Single Frequency Configuration
Multiple Frequency Configuration
These configurations are described on the following pages.
Note about Markers
If you are making computer-controlled measurements using "normal" sweep modes
(Frequency List, Single Point, Ramp, Step, Single Angle, or Swept Angle); measurement
speed will increase with markers turned OFF. Markers will not slow down Fast CW
measurements.
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Single Frequency Configuration
This configuration uses the HP 8530A, RF and LO sources, and a controlling computer.
Only CW measurements are possible.
Stage Description
1 The computer selects the frequency of measurement, RF
power, and other measurement settings.
2 Open-collector TTL measurement triggers are asserted on the
HP 8530A EVENT TRIGGER input. A measurement is taken
for each negative-going TTL trigger. This data is stored in the
HP 8530A 100,000 point FIFO buffer. The HP 8530A can
acquire data at speeds between 1650 and 5000 points per
second, depending on the selected fast CW
whether data is being
expained on this issue later. Data
independently of data
you can have very fast data acquisition, but a slow data
transfer rate could be slowing the overall speed of the
system. More on this topic is explained later.
3 The computer executes a command such as the HP BASIC
TRANSFER command. This reads one data point out of the
buffer. Again, situations can occur where the speed of transfer
can be slower than the actual data acquisition.
transfered
transfer
There are situations where
.
at the same time. More is
acquisition
mode
occurs
, and
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Multiple Frequency/Switching Configuration
Stage Description
1
2
3
4
5
The computer sets source power levels, and other settings to
the RF/LO sources, and microwave receiver.
The computer downloads a frequency list and switch channel
list to the HP 85330A run time controller.
The computer places the HP 85330 into run-time mode.
The HP 85330A sets the first switch position.
The HP 85330A increments the frequency of the RF and LO
sources using high speed TTL lines. (Does not occur on the
very first measurement)
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Refer to Figure 6-2 in the HP 85330A Manual.
If using HP 85330A TTL trigger mode
(RUNt:EVENt:TRIGger TTL):
The HP 85330A waits for a TTL trigger on its EVENT
TRIGGER input.
If using HP 85330A IMMEDIATE trigger mode
(RUNt:EVENt:TRIGger IMM
No input on the HP 85330A EVENT TRIGGER line is required.
Data is acquired immediately (refer to step 7).
Using Time Delays:
A time delay can be set for switch settling time using the
HP 85330A command RUN:SWIT:DEL.
If you need a time delay before
HP 8530A FASPARMTIME command.
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At this time the HP 85330A sends a trigger to the HP 8530A
EVENT TRIGGER input. The data is acquired and stored in the
HP 8530A 100,000 point FIFO buffer. The HP 8530A can
acquire data at speeds between 1650 and 5000 points per
second, depending on the selected fast CW
whether data is being
expained on this issue later. Data
independently of data
you can have very fast data acquisition, but a slow data
transfer rate could be slowing the overall speed of the
system.
The computer executes a command such as the HP BASIC
TRANSFER command. This reads one data point out of the
buffer. Again, situations can occur where the speed of transfer
can be slower than the actual data acquisition.
More on this topic is explained later.
transfered
transfer
any
data aquisition, use the
mode
, and
at the same time. More is
acquisition
. There are situations where
occurs
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What is Fast CW Mode?
The HP 8530A provides two primary methods allowing extremely fast antenna,
RCS, or CW frequency measurements:
Fast CW mode (there are four types of Fast CW mode to choose from.
An optional fast pulse mode is available in HP 8530A H02
Fast CW modes are explained in this section. Fast Pulse is described in the HP 8530A
H02 manual.
There are actually four standard "Fast CW" modes:
Standard Fast CW
Fast Data Collection
Autoranged Data Collection (most commonly used)
Fast IF Multiplexing
Fast CW modes are only available when you are controlling the receiver with a computer.
These modes buffers measurement data in a 100,000 point (First-In First-Out) data buffer.
Each of these modes is explained below.
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Description of the Fast CW Modes
All the Fast CW modes can be externally triggered, using the (TTL) EVENT TRIGGER
input - or over HP-IB.
Table 3. Description of Fast CW Modes
Standard Fast
CW
Measures at rates of up to 5,000 data points per second. This speed is
not sustainable continuously. The reason: at this speed, data is not being
transferred out of the instrument. Once the 100,000 point FIFO buffer is
full the data must be transferred out. Fast CW can sustain a continuous
transfer speed of 3,333 points per second.
Burst data acquisition speed: 5,000 points per second
Sustained data acquisition speed: 3,333 points per second
Handshaking: NO
The allowable point-to-point amplitude variation of the measured signal is
+
12 dB. If you have point-to-point variations greater than +12 dB, use the
Autoranged Data Collection feature, described below.
Fast Data
Collection
This mode is similar to the Fast CW mode, but has one more feature: It
pulls the rear panel STOP SWEEP and RECEIVER READY lines LOW
during data acquisition. These lines go HIGH when the receiver is ready
to take more data. Trigger pulses are ignored when STOP SWEEP is
LOW. This "handshake" allows external hardware to coordinate
measurements.
Burst data acquisition speed: 4,000 points per second
Sustained data acquisition speed: 3,333 points per second
Handshaking:
Adjacent Point to Point Power Variation: +
This mode is recommended when measuring signals that make sudden
changes in amplitude, with an upper limit of +
adjacent measurement data points. (A typical application for this mode is
when a multiplexer is used to switch between antennas.)
STOP SWEEP and RECEIVER READY
12 dB
12 dB between two
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Autoranged
Data
Collection
Use this mode if signal levels vary by more than +
adjacent points. This mode allows you to accurately measure signals
across the full dynamic range of the receiver. This is the mode used when
in TURBO MODE in the ORBIT/FR 959 software, and all near-field
measurement software produced by Nearfield Systems Inc.
Burst data acquisition speed: 2,500 points per second
Sustained data acquisition speed: 2,500 points per second
Handshaking: STOP SWEEP and RECEIVER READY
Adjacent Point to Point Power Variation: Full dynamic range of
reciever
This mode is recommended when measuring signals that make sudden
changes in amplitude between adjacent measurement points. The signal
can change any amount, up to the maximum dynamic range of the
receiver. (A typical application for this mode is when an external PIN
multiplexer is used to switch between antennas. Or when measuring
multiple inputs from a co-polarized and cross-polarized antenna.)
12 dB between
Fast IF
Multiplexing
Mode
This mode switches between up to four measurement
the receiver. This can eliminate the need for pin switches (and the
required VXI controller) in systems measuring up to three
Burst data acquisition speed: 4,000 points per second
Sustained data acquisition speed: 3,333 points per second
Handshaking: STOP SWEEP and RECEIVER READY
The ratios available are: b1/a1, b2/a1, b1/a2, b2/a2. Up to four ratios can
be measured in a predetermined automated sequence.
You can choose to trigger once for all ratios, or require a trigger for each
ratio measured.
ratios
internally to
test signals
.
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Fast Pulse
Mode
(Optional)
This mode only exists in the pulse compatible HP 8530A H02. Turbo
mode systems also require an H02 or H03 version of the HP 85330A.
This mode allows pulsed measurements at rates that are faster than
non-turbo measurements.
Burst data acquisition speed: 1,650 points per second
Sustained data acquisition speed: 1,650 points per second
Handshaking: STOP SWEEP and RECEIVER READY
This mode is discussed in detail in the HP 85330A H02 manual.
Special Note on Averaging
To make averaging work in wideband mode, you have to set the multiple
source offset value to 20.000017 MHz instead of 20 MHz. This setting will
work for normal bandwidth measurements as well.
Perform the following steps:
Press:
[SYSTEM]
{RECEIVER} {OFFSET FREQUENCY}
{MULT. SRC. ON / SAVE}
Averaging only functions in ratioed measurements, not when viewing
individual service channels.
{MORE} {EDIT MULT. SRC.}
20.000017 [MHz]
To use high speed operation you must have a basic understanding of instrument HP-IB
programming.
Which Parameter is Measured in Fast CW Mode?
If you have HP 8530A firmware revision 1.40 or above, you can measure 1 to 4 different
input ratios in Fast CW Mode.
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