3
General Warranty
The material contained in this document is provided “as is,” and is subject to
being changed, without notice, in future editions. Further, to the maximum extent
permitted by applicable law, Keysight disclaims all warranties, either express or
implied with regard to this manual and any information contained herein,
including but not limited to the implied warranties of merchantability and fitness
for a particular purpose. Keysight shall not be liable for errors or for incidental or
consequential damages in connection with the furnishing, use, or performance of
this document or any information contained herein. Should Keysight and the user
have a separate written agreement with warranty terms covering the material in
this document that conflict with these terms, the warranty terms in the separate
agreement shall control. Duration and conditions of warranty for this product may
be superseded when the product is integrated into (becomes a part of) other
Keysight products. During the warranty period, Keysight will, at its option, either
repair or replace products which prove to be defective. The warranty period begins
on the date of delivery or on the date of installation if installed by Keysight.
Restricted Rights Legend
The Software and Documentation have been developed entirely at private
expense. They are delivered and licensed as “commercial computer software” as
defined in DFARS 252.227-7013 (Oct 1988), DFARS 252.211-7015 (May 1991),
or DFARS 252.227-7014 (Jun 1995), as a “commercial item” as defined in FAR
2.101(a), or as “restricted computer software” as defined in FAR 52.227-19
(Jun 1987) (or any equivalent agency regulation or contract clause), whichever is
applicable. You have only those rights provided for such Software and
Documentation by the applicable FAR or DFARS clause or the Keysight standard
software agreement for the product involved.
Keysight N8262A Programming Guide
Equipment Operation
Warnings and Cautions
This guide uses warnings and cautions to denote hazards.
Personal Safety Considerations
This is a Safety Class I product (provided with a protective earthing ground
incorporated in the power cord). The mains plug shall only be inserted in a socket
outlet provided with a protective earth contact. Any interruption of the protective
conductor, inside or outside the instrument, is likely to make the instrument
dangerous. Intentional interruption is prohibited. If this instrument is not used as
specified, the protection provided by the equipment could be impaired. This
instrument must be used in a normal condition (in which all means of protection
are intact) only.
No operator serviceable parts inside. Refer servicing to qualified personnel. To
prevent electrical shock, do not remove covers. For continued protection against
fire hazard, replace the line fuse(s) only with fuses of the same type and rating
(for example, normal blow, time delay, etc.). The use of other fuses or material is
prohibited.
WARNING
A WARNING notice denotes a hazard. It calls attention to an operating
procedure, practice, or the like that, if not correctly performed or adhered to,
could result in personal injury or loss of life. Do not proceed beyond a
WARNING notice until the indicated conditions are fully understood and met.
CAUTION
A CAUTION notice denotes a hazard. It calls attention to an operating
procedure, practice, or the like that, if not correctly performed or adhered to,
could result in damage to the product or loss of important data. Do not
proceed beyond a CAUTION notice until the indicated conditions are fully
understood and met.
Keysight N8262A Programming Guide
5
General Safety Considerations
The following general safety precautions must be observed during all phases of
operation of this instrument. Failure to comply with these precautions or with
specific warnings elsewhere in this manual violates safety standards of design,
manufacture, and intended use of the instrument. Keysight Technologies, Inc.
assumes no liability for the customer’s failure to comply with these requirements.
User Environment
This instrument is designed for indoor use only.
WARNING
– Before this instrument is switched on, make sure it has been properly
grounded through the protective conductor of the ac power cable to a
socket outlet provided with protective earth contact. Any interruption of
the protective (grounding) conductor, inside or outside the instrument, or
disconnection of the protective earth terminal can result in personal
injury.
CAUTION
– Any adjustments or service procedures that require operation of the
instrument with protective covers removed should be performed only by
trained service personnel.
Programming Guide
55
1
Power Meter Remote
Operation
Introduction
56
Configuring the Remote Interface
57
Zeroing and Calibrating the P-Series Power Sensor
59
Making Measurement
61
Using Frequency Dependent Offset Tables
77
Setting the Range, Resolution and Averaging
84
Range
86
Setting Offsets
88
Setting Measurement Limits
90
Getting the Best Speed Performance
94
How Measurements are Calculated
99
Status Reporting
100
Saving and Recalling Power Meter Configurations
106
Using Device Clear to Halt Measurements
107
An Introduction to the SCPI Language
108
SCPI Compliance Information
117
Summary of Commands
119
Making Measurements on Wireless Communication Standards
120
This chapter describes the parameters that configure the power meter and helps
you determine settings to optimize performance.
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Introduction
This chapter describes the parameters which configure the power meter and help
you determine settings to optimize performance. It contains the following
sections:
–
“Configuring the Remote Interface” on page 57.
–
“Zeroing and Calibrating the P-Series Power Sensor” on page 59.
–
“Making Measurement” on page 61.
–
“Using Frequency Dependent Offset Tables” on page 77.
–
“Setting the Range, Resolution and Averaging” on page 84.
–
“Setting Offsets” on page 88.
–
“Setting Measurement Limits” on page 90.
–
“Getting the Best Speed Performance” on page 94.
–
“How Measurements are Calculated” on page 99.
–
“Status Reporting” on page 100.
–
“Saving and Recalling Power Meter Configurations” on page 106.
–
“Using Device Clear to Halt Measurements” on page 107.
–
“An Introduction to the SCPI Language” on page 108.
–
“SCPI Compliance Information” on page 117.
–
“Summary of Commands” on page 119.
–
“Making Measurements on Wireless Communication Standards” on page 120.
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Configuring the Remote Interface
This section briefly describes how to configure the LAN remote interface.
LAN Configuration
The power meter has three LAN operating modes:
–
Dynamic IP (Dynamic Host Configuration Protocol or DHCP)
–
Auto IP (Local PC Control or isolated (non-site) LAN)
–
Static IP (Manual mode)
These three modes can be set up from the P-Series soft front panel. For soft front
panel operation, refer to the P-Series Modular Power Meter Installation Guide.
Configuring the LAN Remotely
To automatically configure the LAN settings, enable DHCP operation using the
SYSTem:COMMunicate:LAN:DHCP[:STATe] command.
In this Dynamic IP mode the IP Address, Subnet Mask, and Default Gateway
values are obtained from a DHCP server. Using this Dynamic IP mode does not
require a detailed knowledge of your network configuration.
The IP Address, Subnet Mask, Default Gateway, and Host settings can be
changed manually or remotely. To individually specify the LAN settings, use the
following commands:
–
IP Address -SYSTem:COMMuniucate:LAN:ADDRess
–
Subnet Mask -SYSTem:COMMunicate:LAN:SMASk
–
Default Gateway -SYSTem:COMMunicate:LAN:DGATeway
NOTE
For more information on configuring the remote interface connectivity, refer to
the Keysight Technologies USB/LAN/GPIB Interfaces Connectivity Guide. If you
have installed the IO Libraries Suite, you can access the Connectivity Guide via
the Keysight IO Libraries Control icon. Alternatively, you can access the
Connectivity Guide via the web at www.keysight.com/find/connectivity.
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–
Domain Name -SYSTem:COMMunicate:LAN:DNAMe
–
Hostname -SYSTem:COMMunicate:LAN:HNAMe
–
Restart Networkk -SYSTem:COMMunicate:LAN:RESTart
The character_data values for the IP address, Subnet Mask, and Default
Gateway can range between 0.0.0.0 and 255.255.255.255.
The LAN setting values are stored in non-volatile memory and are not part of the
save-recall function.
NOTE
If you configure an invalid IP Address or an IP address that is used by another
device or host, an error message is generated. This error can be read by using
the SYSTem:ERRor? command.
NOTE
For more information about Keysight IO Libraries software refer to the
Connectivity Guide. If you have installed other I/O Software, refer to
documentation that accompanies the software.
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59
Zeroing and Calibrating the P-Series Power Sensor
P-Series wideband power sensor’s do not need manual calibration and zero
routines performed. These are performed without removing the power sensor from
the source.
Zeroing
Zeroing adjusts the power meter’s specified channel for a zero power reading.
The command CALibration[1]|2:ZERO:AUTO [ONCE|ON|OFF|0|1] causes the
power meter to perform its zeroing routine on the specified channel when
enabled. This adjusts the power meter for a zero power reading with no power
supplied to the power sensor.
1|ON can only be used with a P-Series sensor. When 1|ON is enabled the zero is
maintained by a combination of zero on-the-fly for measurements and
temperature compensation.
Zeroing of the power meter happens automatically:
–
When a 5 °C change in temperature occurs
–
When you change the power sensor
–
Every 24 hours
–
Prior to measuring low level signals. For example, 10 dB above the lowest
specified power for your power sensor.
Calibration
The command used to calibrate the power meter is:
CALibration[1|2]:AUTO ONCE
It is recommended that you zero the power meter before calibrating.
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Calibration Sequence
This feature allows you to perform a complete calibration sequence with a single
query. The query is:
CALibration[1|2][:ALL]?
The query assumes that the power sensor is connected to the power reference
oscillator. It turns the power reference oscillator on, then after calibrating, returns
the power reference oscillator to the same state it was in prior to the command
being received. The calibration sequence consists of:
1
Zeroing the power meter (CALibration[1|2]:ZERO:AUTO ONCE)
2
Calibrating the power meter (CALibration[1|2]:AUTO ONCE)
The query enters a number into the output buffer when the sequence is complete.
If the result is 0 the sequence was successful. If the result is 1 the sequence failed.
Refer to “CALibration[1]|2[:ALL]?” on page 228 for further information.
NOTE
The CALibration[1|2][:ALL] command is identical to the
CALibration[1|2][:ALL]? query except that no number is returned to indicate
the outcome of the sequence. You can examine the Questionable Status
Register or the error queue to discover if the sequence has passed or failed.
Refer to “Status Reporting” on page 100 for further information.
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Making Measurement
The MEASure? and CONFigure commands provide a straight-forward method to
program the power meter for measurements. You can select the measurement’s
expected power level, resolution and with the N8262A the measurement type
(that is single channel, difference or ratio measurements) all in one command. The
power meter automatically presets other measurement parameters to default
values as shown in Table 1-1 below.
An alternative method to program the power meter is to use the lower level
commands. The advantage of using the lower level commands over the
CONFigure command is that they give you more precise control of the power
meter. As shown in Table 1-1, the CONFigure command presets various states in
the power meter. It may be likely that you do not want to preset these states.
Refer to “Using the Lower Level Commands” on page 75 for further information.
Table 1-1
MEASure? and CONFigure preset states
Command
MEASure? and CONFigure Setting
Trigger source
(TRIGger:SOURce)
Immediate
Filter
(SENSe:AVERage:COUNt:AUTO)
On
Filter
state(SENSe:AVERage:STATe)
On
Trigger cycle
(INITiate:CONTinuous)
Off
Trigger Delay
(TRIGger:DELay:AUTO)
On
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Using MEASure?
The simplest way to program the power meter for measurements is by using the
MEASure? query. However, this command does not offer much flexibility. When
you execute the command, the power meter selects the best settings for the
requested configuration and immediately performs the measurement. You cannot
change any settings (other than the expected power value, resolution and with the
N8262A the measurement type) before the measurement is taken. This means you
cannot fine tune the measurement, for example, you cannot change the filter
length. To make more flexible and accurate measurements use the CONFIGure
command. The measurement results are sent to the output buffer. MEASure? is a
compound command which is equivalent to an ABORT, followed by a CONFigure,
followed by a READ?.
MEASure? Examples
The following commands show a few examples of how to use the MEASure? query
to make a measurement. It is advisable to read through these examples in order as
they become increasingly more detailed. These examples configure the power
meter for a measurement (as described in each individual example), automatically
place the power meter in the “wait-for-trigger” state, internally trigger the power
meter to take one reading, and then sends the reading to the output buffer.
These examples give an overview of the MEASure? query. For further information
on the MEASure? commands refer to the section “MEASure[1]|2|3|4 Commands” on
page 171.
Example 1 - The Simplest Method
The following commands show the simplest method of making single channel
(for example A or B) measurements. Using MEAS1? results in an upper window
measurement, and MEAS2? in a lower window measurement. The channel
associated with the window can be set using the source list parameter
(see Example 2 - Specifying the Source List Parameter), or defaults as in this
example (see “Keysight N8262A” on page 65).
MEAS1?
specifies window
MEAS2?
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Example 2 - Specifying the Source List Parameter
The MEASure command has three optional parameters, an expected power value,
a resolution and a source list. These parameters must be entered in the specified
order. If parameters are omitted, they default from the right. The parameter
DEFault is used as a place holder.
The following example uses the source list parameter to specify the measurement
channel as Channel A. The expected power and resolution parameters are
defaulted, leaving them at their current settings. The measurement is carried out
on the upper window.
The operation of the MEAS1? command when the source list parameter is
defaulted is described in the note “Keysight N8262A” on page 65.
Example 3 - Specifying the Expected Power Parameter
The previous example details the three optional parameters which can be used
with the MEASure? command. The first optional parameter is used to enter an
expected power value. Entering this parameter is only relevant if you are using an
E-Series power sensor. The value entered determines which of the power sensor’s
two ranges is used for the measurement. If the current setting of the power
sensor’s range is no longer valid for the new measurement, specifying the
expected power value decreases the time taken to obtain a result.
The following example uses the expected value parameter to specify a value of
–50 dBm. This selects the power sensor’s lower range (refer to “Range” on
page 86 for details of the range breaks). The resolution parameter is defaulted,
leaving it at its current setting. The source list parameter specifies a Channel B
measurement. The measurement is displayed on the lower window.
MEAS1? DEF,DEF,(@1)
specifies window
specifies channel
MEAS2? -50,DEF,(@2)
specifies window
specifies channel
specifies expected power value
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Example 4 - Specifying the Resolution Parameter
The previous examples detailed the use of the expected value and source list
parameters. The resolution parameter is used to set the resolution of the specified
window. This parameter does not affect the resolution of the data, however it does
affect the auto averaging setting (refer to Figure 1-2).
Since the filter length used for a channel with auto-averaging enabled is
dependent on the window resolution setting, a conflict arises when a given
channel is set up in both windows and the resolution settings are different. In this
case, the higher resolution setting is used to determine the filter length.
The following example uses the resolution parameter to specify a resolution
setting of 3. This setting represents 3 significant digits if the measurement suffix is
W or %, and 0.01 dB if the suffix is dB or dBm. Refer to Chapter 2, “MEASurement
Commands”on page 123, for further details on the resolution parameter. The
expected power and source list parameters are defaulted in the example. The
expected power value remains unchanged at its current setting. The source list
parameter defaults as described in the note “Keysight N8262A” on page 65. Note
that as the source list parameter is the last specified parameter you do not have to
specify DEF. The measurement is carried out on the upper window.
Example 5 - Making a Difference Measurement
The following command is performed on the N8262A. It queries the lower window
to make a difference measurement of Channel B -Channel A. The expected power
and resolution parameters are defaulted, leaving them at their current settings.
MEAS1? DEF,3
specifies window
specifies resolution setting
MEAS2:POW:AC:DIFF? DEF,DEF,(@2),(@1)
specifies window
specifies between which channels
the difference is calculated
Channel B - A
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Example 6 - Making a Ratio Measurement
The following command is performed on the N8262A. It queries the upper window
to make a ratio measurement of Channel A/B. The expected power and resolution
parameters are defaulted, leaving them at their current settings.
MEAS1:POW:AC:RAT? DEF,DEF,(@1),(@2)
specifies window
specifies the relationship of the
channels in the ratio
Channel A / B
NOTE
Keysight N8262A
The operation of the MEASure? command when the source list parameter is
defaulted depends on the current setup of the window concerned (for example,
A, B, A/B, A-B etc.) and on the particular command used (for example,
MEAS[:POW][:AC]? and MEAS:POW:AC:RAT?).
This means that when the source list parameter is defaulted, there are a number
of possibilities.
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Table 1-2
Possibilities of the defaulted source list parameter
Command
Current Window Setup
Measurement
MEAS1[:POW][AC]?
Upper Window:
A
A
B
B
Any Other
Any Other
A
MEAS2[:POW][AC]?
Lower Window:
A
A
B
B
Any Other
B
MEAS1:POW:AC:RAT
Upper Window:
A/B
A/B
B/A
B/A
Any Other
A/B
MEAS2:POW:AC:RAT
Lower Window:
A/B
A/B
B/A
B/A
Any Other
A/B
MEAS1:POW:AC:DIFF?
Upper Window:
A-B
A-B
B-A
B-A
Any Other
A-B
MEAS2:POW:AC:DIFF?
Lower Window:
A-B
A-B
B-A
B-A
Any Other
A-B
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Using the CONFigure Command
When you execute this command, the power meter presets the optimum settings
for the requested configuration (like the MEASure? query). However, the
measurement is not automatically started and you can change measurement
parameters before making measurements. This allows you to change the power
meter’s configuration from the preset conditions. The power meter offers a variety
of low-level commands in the SENSe, CALCulate, and TRIGger subsystems. For
example, if you want to change the averaging use the
[SENSe[1]]|SENSe2:AVERage:COUNt command.
Use the INITiate or READ? query to initiate the measurement.
Using READ?
CONFigure does not take the measurement. One method of obtaining a result is to
use the READ? query. The READ? query takes the measurement using the
parameters set by the CONFigure command then sends the reading to the output
buffer. Using the READ? query obtains new data.
Using INITiate and FETCh?
CONFigure does not take the measurement. One method of obtaining the result is
to use the INITiate and FETCh? commands. The INITiate command causes the
measurement to be taken. The FETCh? query retrieves a reading when the
measurement is complete, and sends the reading to the output buffer. FETCh? can
be used to display the measurement results in a number of different formats (for
example, A/B and B/A) without taking fresh data for each measurement.
CONFigure Examples
The following program segments show how to use the commands READ?,
INITiate and FETCh? and CONFigure to make measurements.
It is advisable to read through these examples in order as they become
increasingly more detailed.
These examples give an overview of the CONFigure command. For further
information on the CONFigure commands refer to Chapter 2, "MEASurement
Commands".
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Example 1 - The Simplest Method
The following program segments show the simplest method of querying the upper
and lower window’s measurement results respectively.
Using READ?
Using INITiate and FETCh?
Example 2 - Specifying the Source List Parameter
The CONFigure and READ? commands have three optional parameters, an
expected power value, a resolution and a source list. These parameters must be
entered in the specified order. If parameters are omitted, they default from the
right. The parameter DEFault is used as a place holder.
*RST
Reset instrument
CONF1
Configure upper window -defaults to a Channel A measurement
READ1?
Take upper window (Channel A) measurement
*RST
Reset instrument
CONF2
Configure lower window -defaults to a Channel B measurement
READ2?
Take lower window measurement (Channel B)
*RST
Reset instrument
CONF1
Configure upper window -defaults to a Channel A measurement
INIT1?
Causes Channel A to make a measurement
FETC1?
Retrieves the upper window’s measurement
*RST
Reset instrument
CONF2
Configure lower window
INIT2?
Causes Channel B to make a measurement
FETC2?
Retrieves the lower window’s measurement
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The following examples use the source list parameter to specify the measurement
channel as Channel A. The expected power and resolution parameters are
defaulted, leaving them at their current settings. The measurement is carried out
on the upper window.
Although the READ? and FETCh? queries have three optional parameters it is not
necessary to define them as shown in these examples. If they are defined they
must be identical to those defined in the CONFigure command otherwise an error
occurs.
Using READ?
Using INITiate and FETCh?
Example 3 - Specifying the Expected Power Parameter
The previous example details the three optional parameters which can be used
with the CONFigure and READ? commands. The first optional parameter is used to
enter an expected power value. Entering this parameter is only relevant if you are
using an E-Series power sensor. The value entered determines which of the power
sensor’s two ranges is used for the measurement. If the current setting of the
power sensor’s range is no longer valid for the new measurement, specifying the
expected power value decreases the time taken to obtain a result.
ABOR1
Aborts Channel A
CONF1 DEF,DEF,(@1)
Configures the upper window to make a
Channel A measurement using the current
expected power and resolution settings
READ1?
Takes the upper window’s measurement
ABOR1
Aborts Channel A
CONF1 DEF,DEF,(@1)
Configures the upper window to make a
Channel A measurement using the current
expected power and resolution settings
INIT1
Causes Channel A to make a measurement
FETC1? DEF,DEF,(@1)
Retrieves the upper window’s measurement
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The following example uses the expected value parameter to specify a value of
–50 dBm. This selects the power meter’s lower range (refer to “Range” on page 86
for details of the range breaks). The resolution parameter is defaulted, leaving it at
its current setting. The source list parameter specifies a Channel B measurement.
The measurement is carried out on the upper window.
Using READ?
Some fine tuning of measurements can be performed using the CONFigure and
READ? commands. For example, in the above program segment some fine tuning
can be performed by setting the filter length to 1024 and the trigger delay off.
1
ABOR2
2
CONF1 -50,DEF,(@2)
3
SENS2:AVER:COUN 1024
4
TRIG2:DEL:AUTO OFF
5
READ1?
Using INITiate and FETCh?
ABOR2
Aborts Channel B
CONF1 -50,DEF,(@2)
Configures the upper window to make a
Channel B measurement using an expected
power of –50 dBm and the current resolution
setting
READ1?
Takes the upper window’s measurement
ABOR2
Aborts Channel B
CONF1 -50,DEF,(@2)
Configures the upper window to make a Channel
B measurement using an expected power of
–50 dBm and the current resolution setting
INIT2
Causes Channel B to make a measurement
FETC1? -50,DEF,(@2)
Retrieves the upper window’s measurement
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Some fine tuning of measurements can be carried out using the CONFigure
command and INITiate and FETCh? commands. For example, in the above
program segment some fine tuning can be carried out by setting the filter length
to 1024 and the trigger delay off.
1
ABOR2
2
CONF1 -50,DEF,(@2)
3
SENS2:AVER:COUN 1024
4
TRIG2:DEL:AUTO OFF
5
INIT2
6
FETC1? -50,DEF,(@2)
Example 4 - Specifying the Resolution Parameter
The previous examples detailed the use of the expected value and source list
parameters. The resolution parameter is used to set the resolution of the specified
window. This parameter does not affect the resolution of the data, however it does
affect the auto averaging setting (refer to Figure 1-2 on page 85).
Since the filter length used for a channel with auto-averaging enabled is
dependent on the window resolution setting, a conflict arises when a given
channel is set up in both windows and the resolution settings are different. In this
case, the higher resolution setting is used to determine the filter length.
The following example uses the resolution parameter to specify a resolution
setting of 3. This setting represents 3 significant digits if the measurement suffix is
W or %, and 0.01 dB if the suffix is dB or dBm (for further details on the resolution
parameter refer to the commands in Chapter 2, "MEASurement Commands").
Also, in this example the expected power and source list parameters are
defaulted. The expected power value is left unchanged at its current setting. The
source list parameter is defaulted as described in the note “Keysight N8262A” on
page 65. Note that as the source list parameter is the last specified parameter you
do not have to specify DEF.
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Using READ?
Some fine tuning of the above program segment can be carried out for example,
by setting the trigger delay off. The following program segment assumes that
Channel A is currently being measured on the upper window.
1
ABOR1
2
CONF1 DEF,3
3
TRIG1:DEL:AUTO OFF
4
READ1?
Using INITiate and FETCh?
The following program segment assumes that Channel A is currently being
measured on the upper window.
ABOR1
Aborts Channel A
CONF1 DEF,3
Configures the upper window to make a measurement
using the current setting of the expected power and
source list and a resolution setting of 3
READ1?
Takes the upper window’s measurement. This is Channel A
or B measurement depending on current window setup.
ABOR1
Aborts Channel A
CONF1 DEF,3
Configures the upper window to make a measurement
using the current setting of the expected power and
source list and a resolution setting of 3
INIT1
Causes Channel A to make a measurement
FETC1? DEF,3
Retrieves the upper window’s measurement
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Some fine tuning of the above program segment can be carried out for example,
by setting the trigger delay off.
1
ABOR1
2
CONF1 DEF,3
3
TRIG1:DEL:AUTO OFF
4
INIT1:IMM
5
FETC1? DEF,3
Example 5 - Making a Difference Measurement
The following program segment can be carried out on the N8262A. It queries the
lower window to make a difference measurement of Channel A -Channel B. The
expected power level and resolution parameters are defaulted, leaving them at
their current settings. Some fine tuning of the measurement is carried out by
setting the averaging, and the trigger delay to off.
Using READ?
ABOR1
ABOR2
CONF2:POW:AC:DIFF DEF,DEF,(@1),(@2)
SENS1:AVER:COUN 1024
SENS2:AVER:COUN 1024
TRIG1:DEL:AUTO OFF
TRIG2:DEL:AUTO OFF
READ2:POW:AC:DIFF?
READ2:POW:AC:DIFF? DEF,DEF,(@2),(@1) (A second READ? query is sent to make
a Channel B -Channel A measurement using fresh measurement data).
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Using INITiate and FETCh?
ABOR1
ABOR2
CONF2:POW:AC:DIFF DEF,DEF,(@1),(@2)
SENS1:AVER:COUN 1024
SENS2:AVER:COUN 1024
TRIG1:DEL:AUTO OFF
TRIG2:DEL:AUTO OFF
INIT1:IMM
INIT2:IMM
FETC2:POW:AC:DIFF?
FETC2:POW:AC:DIFF? DEF,DEF,(@2),(@1) (A second FETCh? query is sent to
make a Channel B -Channel A measurement using the current measurement
data).
Example 6 - Making a Ratio Measurement
The following program segment can be carried out on the N8262A. It queries the
lower window to make a ratio measurement of Channel A/B. The expected power
level and resolution parameters are defaulted, leaving them at their current
settings. Some fine tuning of the measurement is carried out by setting the
averaging.
Using READ?
ABOR1
ABOR2
CONF2:POW:AC:RAT DEF,DEF,(@1),(@2)
SENS1:AVER:COUN 512
SENS2:AVER:COUN 256
READ2:POW:AC:RAT?
READ2:POW:AC:RAT? DEF,DEF,(@2),(@1) (A second READ? query is sent to make
a Channel B -Channel A ratio measurement using fresh measurement data.)
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Using INITiate and FETCh?
ABOR1
ABOR2
CONF2:POW:AC:RAT DEF,DEF,(@1),(@2)
SENS1:AVER:COUN 512
SENS2:AVER:COUN 256
INIT1:IMM
INIT2:IMM
FETC2:POW:AC:RAT?
FETC2:POW:AC:RAT? DEF,DEF,(@2),(@1) (A second FETCh? query is sent to make
a Channel B -Channel A measurement using the current measurement data.)
Using the Lower Level Commands
An alternative method of making measurements is to use the lower level
commands to set up the expected range and resolution. This can be done using
the following commands:
[SENSe[1]]|SENSe2:POWER:AC:RANGe
DISPlay[:WINDow[1|2]]:RESolution
The measurement type can be set using the following commands in the
CALCulate subsystem:
CALCulate[1|2]:MATH[:EXPRession]
CALCulate[1|2]:RELative[:MAGNitude]
The advantage of using the lower level commands over the CONFigure command
is that they give you more precise control of the power meter. As shown in
Table 1-1 the CONFigure command presets various states in the power meter. It
may be likely that you do not want to preset these states.
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Example
The following example sets the expected power value to –50 dBm and the
resolution setting to 3 using the lower level commands. The measurement is a
single Channel A measurement carried out on the lower window.
ABOR1
Aborts Channel A
CALC2:MATH:EXPR "(SENS1)" Displays Channel A on lower window
SENS1:POW:AC:RANG -50
Sets lower range (E-Series sensors only)
DISP:WIND2:RES 3
Sets the lower window’s resolution to setting 3
INIT1
Causes Channel A to make a measurement
FETC2?
Retrieves the lower window’s measurement
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Using Frequency Dependent Offset Tables
This section describes how to use frequency dependent offset tables. These tables
give you the ability to compensate for frequency effects in your test setup.
Overview
If the [SENSe[1]]|SENSe2:CORRection:CSET2:STATe command is OFF, the
frequency dependent offset tables are not used. When
[SENSe[1]]|SENSe2:CORRection:CSET2:STATe is ON, the frequency dependent
offset tables are used, providing you with a quick and convenient method of
compensating for your external test setup over a range of frequencies. Note that
when selected, frequency dependent offset correction is IN ADDITION to any
correction applied for sensor frequency response. The power meter is capable of
storing 10 frequency dependent offset tables of 80 frequency points each.
To use frequency dependent offset tables you:
1
Edit a frequency dependent offset table if necessary.
2
Select the frequency dependent offset table.
3
Enable the frequency dependent offset table.
4
Zero and calibrate the power meter.
If you are using an 8480 Series sensor the reference calibration factor used
during the calibration must be entered manually.
5
Specify the frequency of the signal you want to measure. The required offset is
automatically set by the power meter from the frequency dependent offset
table.
6
Make the measurement.
Figure 1-1 Illustrates how frequency dependent offset tables operate.
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Figure 1-1
Frequency dependent offset tables
TABLE N
FREQ
FREQ
1
.
.
.
.
.
.
.
.
.
.
.
FREQ
2
80
OFFSET
OFFSET
1
.
.
.
.
.
.
.
.
.
.
.
80
TABLE 1
FREQ
FREQ
1
.
.
.
.
.
.
.
.
.
.
.
FREQ
2
80
OFFSET
OFFSET
1
.
.
.
.
.
.
.
.
.
.
.
2
80
TABLE 10
FREQ
FREQ
1
.
.
.
.
.
.
.
.
.
.
.
FREQ
2
80
OFFSET
OFFSET
1
.
.
.
.
.
.
.
.
.
.
.
OFFSET
2
80
OFFSET = Frequency Dependent Offset
FREQ
FREQ
1
.
.
.
.
.
.
.
.
.
.
.
FREQ
2
80
OFFSET
OFFSET
1
.
.
.
.
.
.
.
.
.
.
.
OFFSET
2
80
Frequency of the signal you want
to measure
TABLE SELECTED
OFFSET
2
OFFSET
Frequency dependent
offset used to make
Measurement. Calculated
by the power meter using
linear interpolation.
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Editing Frequency Dependent Offset Tables
It is not possible to create any additional frequency dependent offset tables.
However, the 10 existing tables can be edited using the MEMory subsystem. To do
this:
1
Select one of the existing tables using:
MEMory:TABle:SELect
For information on naming frequency dependent offset tables see “Naming
Frequency Dependent Offset Tables” on page 81. For information on the
current names which you can select refer to “Listing the Frequency Dependent
Offset Table Names” on page 80.
2
Enter the frequency data using:
MEMory:TABle:FREQuency {,}
3
Enter the offset factors as shown in the table below using:
MEMory:TABle:GAIN {,}
4
If required, rename the frequency dependent offset table using:
MEMory:TABLe:MOVE ,. The first parameter
identifies the existing table name, and the second identifies the new table
name.
Frequency
Offset
Frequency 1
Offset 1
Frequency 2
Offset 2
"
"
Frequency n
Offset n
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Listing the Frequency Dependent Offset Table Names
To list the frequency dependent offset tables currently stored in the power meter,
use the following command:
MEMory:CATalog:TABLe?
Note that all tables are listed; including sensor calibration tables.
The power meter returns the data in the form of two numeric parameters and a
string list representing all stored tables.
–
,{,}
The first numeric parameter indicates the amount of memory, in bytes, used
for storage of tables. The second parameter indicates the memory, in bytes,
available for tables.
Each string parameter returned indicates the name, type and size of a stored
frequency dependent offset table:
NOTE
The legal frequency suffix multipliers are any of the IEEE suffix multipliers, for
example, KHZ, MHZ, and GHZ. If no units are specified the power meter assumes
the data is Hz.
PCT is the only legal unit for offset factors and can be omitted.
The frequency and offset data must be within range. Refer to the individual
commands in Chapter 4 for their specified ranges.
Any offset values entered into the table should exclude the effect of the sensor.
Characterization of the test setup independently of the sensor allows the same
table to be used with any sensor.
Ensure that the frequency points you use cover the frequency range of the
signals you want to measure. If you measure a signal with a frequency outside
the frequency range defined in the frequency dependent offset table, then the
power meter uses the highest or lowest frequency point in the table to calculate
the offset.
To make subsequent editing of a frequency dependent offset table simpler, it is
recommended that you retain a copy of your data in a program.
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–
,,
The , and are all character data. The is always
TABL. The is displayed in bytes.
For example, a sample of the response may look like:
560,8020,“Offset_1,TABL,220”,”Offset_2,TABL,340” ....
Naming Frequency Dependent Offset Tables
To rename a frequency dependent offset table use:
MEMory:TABLe:MOVE ,
The first parameter identifies the existing table name, and the second
identifies the new table name.
The following rules apply to frequency dependent offset table names:
1
Table names use a maximum of 12 characters.
2
All characters must be upper or lower case alphabetic characters, or numeric
(0-9), or an underscore (_).
No spaces are allowed in the name.
Reviewing Table Data
To review the data stored in a frequency dependent offset table, use the following
commands:
MEMory:TABLe:SELect "Offset1"
Select the sensor calibration table named “Offset1”.
MEMory:TABLe:SELect?
Query command which returns the name of the currently selected table.
MEMory:TABLe:FREQuency:POINTs?
Query command which returns the number of stored frequency points.
MEMory:TABLe:FREQuency?
Query command which returns the frequencies stored in the frequency dependent
offset table (in Hz).
MEMory:TABLe:GAIN[:MAGNitude]:POINTs?
Query command which returns the number of offset factor points stored in the
frequency dependent offset table.
MEMory:TABLe:GAIN[:MAGNitude]?
Query command which returns the offset factors stored in the frequency
dependent offset table.
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Modifying Data
If you need to modify the frequency and offset factor data stored in a frequency
dependent offset table you need to resend the complete data lists.
If you have retained the original data in a program, edit the program and resend
the data.
Selecting a Frequency Dependent Offset Table
After you have created the frequency dependent offset table, you can select it
using the following command:
[SENSe[1]]|SENSe2:CORRection:CSET2[:SELect]
To find out which frequency dependent offset table is currently selected, use the
query:
[SENSe[1]]|SENSe2:CORRection:CSET2[:SELect]?
Enabling a Frequency Dependent Offset Table
To enable the frequency dependent offset table, use the following command:
[SENSe[1]]|SENSe2:CORRection:CSET2:STATe ON
If you set [SENSe[1]]|SENSe2:CORRection:CSET2:STATe to ON and no frequency
dependent offset table is selected error –221, “Settings conflict” occurs.
Making the Measurement
To make the power measurement, set the power meter for the frequency of the
signal you want to measure. The power meter automatically sets the calibration
factor. Use either the INITiate, FETCh? or the READ? query to initiate the
measurement as shown in the following program segments:
INITiate Example
ABORt1
CONFigure1:POWer:AC DEF,1,(@1)
SENS1:CORR:CSET2:SEL "Offset1"
SENS1:CORR:CSET2:STAT ON
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SENSe1:FREQuency 500KHZ
INITiate1:IMMediate
FETCh1?
READ? Example
ABORt1
CONFigure1:POWer:AC DEF,2,(@1)
SENS1:CORR:CSET2:SEL "Offset1"
SENS1:CORR:CSET2:STAT ON
SENSe1:FREQuency 500KHZ
READ1?
NOTE
If the measurement frequency does not correspond directly to a frequency in the
frequency dependent offset table, the power meter calculates the offset using
linear interpolation.
If you enter a frequency outside the frequency range defined in the frequency
dependent offset table, then the power meter uses the highest or lowest
frequency point in the table to set the offset.
To find out the value of the offset being used by the power meter to make a
measurement, use the query command:
SENSe:CORRection:GAIN4|FDOFfset[:INPut][MAGNITUDE]?
The response may be an interpolated value.
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Setting the Range, Resolution and Averaging
This section provides an overview of setting the range, resolution and averaging.
For more detailed information about these features, refer to the individual
commands in Chapter 10, "SENSe Subsystem".
Resolution
You can set the window’s resolution using the following command:
DISPlay[:WINDow[1]|2][:NUMeric[1]|2]
:RESolution
There are four levels of resolution available (1 through 4).
When the measurement suffix is W or % this parameter represents the number of
significant digits. When the measurement suffix is dB or dBM, 1 through 4
represents 1, 0.1, 0.01, and 0.001 dB respectively.
Refer to the :RESolution command on page 265 for further information.
Averaging
The power meter has a digital filter to average power readings. The number of
readings averaged can range from 1 to 1024. This filter is used to reduce noise,
obtain the desired resolution and to reduce the jitter in the measurement results.
However, the time to take the measurement is increased. You can select the filter
length or you can set the power meter to auto filter mode. To enable and disable
averaging use the following command:
[SENSe[1]]|SENSe2:AVERage[:STATe]
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Auto Averaging Mode
To enable and disable auto filter mode, use the following command:
[SENSe[1]]|SENSe2:AVERage:COUNt:AUTO
When the auto filter mode is enabled, the power meter automatically sets the
number of readings averaged together to satisfy the filtering requirements for
most power measurements. The number of readings averaged together depends
on the resolution and the power level currently being measured. Figure 1-2 lists
the number of readings averaged for each range and resolution when the power
meter is in auto filter mode.
Figure 1-2
Typical averaged readings on 8480 Series sensors
NOTE
Figure 1-2 applies to 8480 Series sensors only.
10 dB
10 dB
Minimum Sensor Power
Maximum Sensor Power
Power Sensor
Dynamic Range
10 dB
10 dB
1
2
3
4
8
8
128
128
Resolution Setting
Number of Averages
1
1
16
256
1
1
2
32
1
1
1
16
1
1
1
8
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Figure 1-3 Illustrates part of the power sensor dynamic range hysteresis.
Figure 1-3
Averaging range hysteresis
Filter Length
You specify the filter length using the following command:
[SENSe[1]]|SENSe2:AVERage:COUNt
The range of values for the filter length is 1 to 1024. Specifying this command
disables automatic filter length selection. Increasing the value of the filter length
reduces measurement noise. However, the time to take the measurement is
increased.
Range
The power meter has no internal ranges which can be set. The only ranges that
can be set are those of the E-Series power sensor. With an E-Series power sensor
the range can be set either automatically or manually. Use autoranging when you
are not sure of the power level you will be measuring.
Minimum Sensor Power
Minimum Sensor Power + 10 dB
Range Hysteresis
10.5 dB
9.5 dB
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Setting the Range
To set the range manually use the following command:
[SENSe[1]]|SENSe2:POWer:AC:RANGe
If the is set to:
–
0, the sensor’s lower range is selected. (For example, this range is –70 to
–13.5 dBm for the E4412A power sensor.)
–
1, the sensor’s upper range is selected. (For example, this range is –14.5 to
+20 dBm for the E4412A power sensor.)
For details on the range limits of other E-Series power sensor refer to the
appropriate power sensor manual.
For further information on this command refer to page 391.
To enable autoranging use the following command:
[SENSe[1]]|SENSe2:POWer:AC:RANGe:AUTO ON
Use autoranging when you are not sure of the power level you will be measuring.
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Setting Offsets
Channel Offsets
The power meter can be configured to compensate for signal loss or gain in your
test setup (for example, to compensate for the loss of a 10 dB attenuator). You use
the SENSe command subsystem to configure the power meter. Gain and loss
correction are a coupled system. This means that a gain set by
[SENSe[1]]|SENSe2:CORRection:GAIN2 is represented in the
[SENSe[1]]|SENSe2:CORRection:LOSS2? command. If you enter an offset value
the state is automatically enabled. However it can be enabled and disabled using
either the [SENSe[1]]|SENSe2:CORRection:GAIN2:STATe or
[SENSe[1]]|SENSe2:CORRection:LOSS2:STATe commands.
LOSS2 is coupled to GAIN2 by the equation
when the default unit is
linear, and
when the default is logarithmic.
Display Offsets
Display offset values can be entered using the
CALCulate[1|2]:GAIN[:MAGNitude] command. CALCulate[1|2]:GAIN:STATe
must be set to ON to enable the offset value. If you enter an offset value the state is
automatically enabled. This offset is applied after any math calculations (refer to
Figure 1-6 on page 99).
Example
The following example program, in HP Basic, details how to use the channel and
display offsets on an N8262A making a Channel A/B ratio measurement.
The final result is:
Loss
1
Gain
---------
=
Gain
–Loss
=
NOTE
You can only use LOSS2 and GAIN2 for external losses and gains. LOSS1 and GAIN1
are specifically for calibration factors.
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10 !Create I/O path name
20 ASSIGN @POWER TO 713
30 !Clear the power meter’s interface
40 CLEAR @POWER
50 !Set the power meter to a known state
60 OUTPUT @POWER;"*RST"
70 !Configure the Power Meter to make the measurement
80 OUTPUT @Power;"CONF:POW:AC:RAT 20DBM,2,(@1),(@2)"
90 !Set the measurement units to dBm
100 OUTPUT @POWER;"UNIT:POW DBM"
110 !Set the power meter for channel offsets of -10 dB
120 OUTPUT @POWER;"SENS1:CORR:GAIN2 -10"
130 OUTPUT @POWER;"SENS2:CORR:GAIN2 -10"
140 !Enable the gain correction
150 OUTPUT @POWER;"SENS:CORR:GAIN2:STATe ON"
160 OUTPUT @POWER;"SENS2:CORR:GAIN2:STATe ON"
170 !Set the power meter for a display offset of -20 dB
180 OUTPUT @POWER;"CALC1:GAIN -20 DB"
190 PRINT "MAKING THE MEASUREMENT"
200 !Initiate the measurement
210 OUTPUT @Power;"INIT1:IMM"
220 OUTPUT @Power;"INIT2:IMM"
230 ! ... and get the result
240 OUTPUT @Power;"FETC:POW:AC:RAT? 20DBM,2,(@1),(@2)"
250 ENTER @Power;Reading
260 !
270 PRINT "The measurement result is ";Reading;"dB."
280 END
For further information on channel offsets refer to page 379. For further
information on display offsets refer to page 192.
AdBm
10
–
BdBm
– 10
----------------------
– 20
dB
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Setting Measurement Limits
You can configure the power meter to detect when a measurement is outside of a
predefined upper and/or lower limit value.
Limits are window or measurement display line based and can be applied to
power, ratio or difference measurements.
Setting Limits
The power meter can be configured to verify the power being measured against
an upper and/or lower limit value. The range of values that can be set for lower
and upper limits is –150.00 dBm to +230.00 dBm. The default upper limit is
+90.00 dBm and the default lower limit is –90.00 dBm.
A typical application for this feature is shown in Figure 1-4.
Figure 1-4
Limits checking application
CHANNEL A
INPUT
IN
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Figure 1-5
Limits checking results
The range of values that can be set for the upper and lower limits and the default
values depends on the measurement units in the currently measurement line - see
Table 1-3.
+4 dBm
+10 dBm
Amplitude
Frequency
o
o
o
o
o
o
o
Fail
Fail
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Checking for Limit Failures
There are two ways to check for limit failures:
1
Use the SENSe:LIMit:FAIL? and SENSe:LIMit:FCOunt? commands for
channel limits or the
CALCulate[1|2]:LIMit:FAIL? and the
CALCulate[1|2]:LIMit:FCOunt? for window limits
2
Use the STATus command subsystem
Using SENSe and CALCulate
Using SENSe to check the channel limit failures in Figure 1-5 would return the
following results:
Use the equivalent CALCulate commands for checking window limit failures.
Table 1-3
Range of values for window limits
Window
Units
Default
Maximum
Minimum
Maximum
Minimum
dB
+200 dB
–180 dB
60 dB
–120 dB
dBm
+230 dBm
–150 dBm
90 dBm
–90 dBm
%
999.9 X%
100.0 a%
100.0 M%
100.0 p%
W
100.000 XW
1.000 aW
1.000 MW
1.000 pW
SENSe:LIMit:FAIL?
Returns 1 if there has been 1 or more
limit failures or 0 if there have been
no limit failures. In this case 1 is
returned.
SENSe:LIMit:FCOunt?
Returns the total number of limit
failures, in this case 2.
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Using STATus
You can use the STATus subsystem to generate an SRQ to interrupt your program
when a limit failure occurs. This is a more efficient method than using SENSe or
CALCulate, since you do not need to check the limit failures after every power
measurement.
Refer to “Status Reporting” on page 100 and “STATus Subsystem” on page 419 for
further information.
NOTE
If TRIGger:DELay:AUTO is set to ON, then the number of failures returned by
SENSe:LIMit:FCOunt? or CALCulate[1|2]:LIMit:FCOunt? is affected by the
current filter settings.
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Getting the Best Speed Performance
This section discusses the factors that influence the speed of operation (number
of readings/sec) of a P-Series modular power meter.
The following factors are those which have the greatest effect upon measurement
speed (in no particular order):
–
The selected measurement rate, i.e. NORMal, DOUBle, FAST.
–
The sensor being used.
–
The trigger mode (for example, free run, trigger with delay etc.).
–
The output format: ASCii or REAL.
–
The units used for the measurement.
–
The command used to take a measurement.
In addition, in FAST mode there are other influences which are described in “Fast
Mode” on page 98.
The following paragraphs give a brief description of the above factors and how
they are controlled from SCPI.
Measurement Rate
There are three possible speed settings NORMal, DOUBle and FAST. These are set
using the SENSe:MRATe command and can be applied to each channel
independently.
In NORMal and DOUBle modes, full instrument functionality is available and these
settings can be used with all sensors. FAST mode is only available for the P-Series
and E-Series sensors. Also, in FAST mode averaging, limits and ratio/difference
math functions are disabled.
Refer to “Specifications” in the P-Series Modular Power Meter User’s Guide to see
the influence of these speed settings on the accuracy and noise performance of
the power meter.
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Sensor
Different measurement rates are achievable depending on the sensor type being
used, as shown in Table 1-4:
Trigger Mode
The power meter has a very flexible triggering system. For simplicity, it can be
described as having three modes:
–
Free Run: When a channel is in Free Run, it continuously takes measurements
on this channel. A channel is in free run when INITiate:CONTinuous is set to
ON and TRIGger:SOURce is set to IMMediate.
–
Triggered Free Run: When a channel is in Triggered Free Run Continuous
Trigger, it takes a new measurement each time a trigger event is detected. A
channel is in Triggered Free Run Continuous Trigger when
INITiate:CONTinuous is set to ON and TRIGger:SOURce is not set to
IMMediate.
–
Single Shot: When a channel is in Single Shot, it takes a new measurement
when a trigger event is detected and then returns to the idle state. A channel is
in Single Shot when INITiate:CONTinuous is set to OFF. Note that a
measurement can take several INT/EXT triggers depending on the filter
settings. Refer to “TRIGger[1]|2:DELay:AUTO ” on page 580 for
further information.
Table 1-4
Model of sensor and measurement rates
Sensor
Measurement Rate
NORMal
DOUBle
FAST
8480 Series
20 reading/s
40 reading/s
NA
E-Series E4410 and E9300
50 ms
20 reading/s
25 ms
40 reading/s
Up to 400
P-Series
50 ms
20 reading/s
25 ms
40 reading/s
Up to 1500
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Trigger with Delay
This can be achieved using the same sequences above (apart from the second)
with TRIG:DEL:AUTO set to ON. Also, the MEAS? command operates in trigger with
delay mode.
In trigger with delay mode, a measurement is not completed until the power
meter filter is full. In this way, the reading returned is guaranteed to be settled. In
all other modes, the result returned is simply the current result from the filter and
may or may not be settled. This depends on the current length of the filter and the
number of readings that have been taken since a change in power level.
With trigger with delay enabled, the measurement speed can be calculated
roughly using the following equation:
readings/sec = speed (as set by SENSe:SPEed)/filter length
For example, with a filter length of 4 and SENS:SPE set to 20, approximately 5
readings/sec is calculated by the power meter.
Typically, free run mode provides the best speed performance from the power
meter (especially in 200 readings/sec mode).
NOTE
A trigger event can be any of the following:
–
The input signal meeting the trigger level criteria.
–
Auto-level triggering being used.
–
A TRIGger GET or *TRG command being sent.
–
An external TTL level trigger being detected.
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Output Format
The power meter has two output formats for measurement results: ASCii and
REAL. These formats are selected using the FORMat command. When FORMat is set
to REAL, the returned result is in IEEE 754 floating-point format (note that the byte
order can be changed using FORMat:BORDer) plus as an end sentinel of the
block.
The REAL for mat is likely to be required only for FAST mode as it reduces the
amount of bus traffic.
Units
The power meter can output results in either linear or log units. The internal units
are linear, therefore optimal performance is achieved when the results output are
also in linear units (since the overhead of performing a log function is removed).
Command Used
In Free Run mode, FETCh? must be used to return a result.
In other trigger modes, there are a number of commands which can be used, for
example, MEASure?, READ?, FETCh? Note that the MEAS? and READ? commands
are compound commands—they perform a combination of other lower level
commands. Typically, the best speed performance is achieved using the low level
commands directly.
Trigger Count
To get the fastest measurement speed the a TRIG:COUNT must be set to return
multiple measurements for each FETCh command. For average only
measurements a count of 4 is required, however, 10 is recommended. In normal
mode (peak measurements) a count of 50 is required to attain 1000 readings per
second.
Power Meter Remote Operation
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Keysight N8262A Programming Guide
Fast Mode
In the highest speed setting, the limiting factor tends to be the speed of the
controller being used to retrieve results from the power meter, and to a certain
extent, the volume of remote traffic. The latter can be reduced using the FORMat
REAL command to return results in binary format. The former is a combination of
two factors:
–
the hardware platform being used
–
the programming environment being used
Power Meter Remote Operation
1
Keysight N8262A Programming Guide
99
How Measurements are Calculated
Figure 1-6 details how measurements are calculated. It shows the order in which
the various power meter functions are implemented in the measurement
calculation.
Figure 1-6
How measurement are calculated
The MEASure commands in this figure can be replaced with the FETCh? and READ?
commands.
TRIGger
DISPlay
WINDow2
:FORMat
:METer
:SELect [1]|2
:NUMeric[1]:RESolution
:NUMeric2:RESolution
Upper Meas
Lower Meas
UNIT4
Conversion
:POW
CALCulate2
Maths
Offset
Relative
Limits
:MATH
:GAIN
:REL
:LIM
Switch
Switch
:FEED
UNIT2
Conversion
:POW
UNIT3
Conversion
:POW
UNIT1
Conversion
:POW
CALCulate4
Maths
Offset
Relative
Limits
:MATH
:GAIN
:REL
:LIM
Switch
Switch
:FEED
CALCulate1
Maths
Offset
Relative
Limits
:MATH
:GAIN
:REL
:LIM
Switch
Switch
:FEED
CALCulate3
Maths
Offset
Relative
Limits
:MATH
:GAIN
:REL
:LIM
Switch
Switch
:FEED
[WINDow[1]]
:FORMat
:METer
:SELect [1]|2
:NUMeric[1]:RESolution
:NUMeric2:RESolution
Upper Meas
Lower Meas
SENSe1
Sensor
Filter
Freq.
Corr.
Offset
Duty
Cycle
:SPEed
:POW:AC:RANG
:POW:AC:RANG:AUTO:DIR
:DET:FUNC
:AVER[1]
:FREQ
:CORR:CFAC
:CORR:CSET
:CORR:GAIN2
:CORR:LOSS2
:CORR:DCYC
Video
Filter
Data
Selection
:BAND:VID (B/W)
:AVER2 (video averaging)
:SWEep:TIME:GATE:DELay
:SWEep:TIME:GATE:LENGth
SENSe2
Sensor
Filter
Freq.
Corr.
Offset
Duty
Cycle
:SPEed
:POW:AC:RANG
:POW:AC:RANG:AUTO:DIR
:DET:FUNC
:AVER[1]
:FREQ
:CORR:CFAC
:CORR:CSET
:CORR:GAIN2
:CORR:LOSS2
:CORR:DCYC
Video
Filter
Data
Selection
:BAND:VID (B/W)
:AVER2 (video averaging)
:SWEep:TIME:GATE:DELay
:SWEep:TIME:GATE:LENGth
:CONTrast
:ENABle
:FORMat
FORMat
Switch
Switch
Switch
Switch
MEAS?
READ?
FETC?
CONF
TRACe:DATA?
“TRACe1”
TRACe:DATA?
“TRACe2”
WINDow1
WINDow2
Power Meter Remote Operation
100
Keysight N8262A Programming Guide
Status Reporting
Status reporting is used to monitor the power meter to determine when events
have occurred. Status reporting is accomplished by configuring and reading
status registers.
The power meter has the following main registers:
–
Status Register
–
Standard Event Register
–
Operation Status Register
–
Questionable Status Register
–
Device Status Register
There are other registers that exist “behind” the main registers, and are described
later in this chapter.
Status and Standard Event registers are read using the IEEE-488.2 common
commands.
Operation and Questionable Status registers are read using the SCPI STATus
command subsystem.
The General Status Register Model
The generalized status register model shown in Figure 1-7 is the building block of
the SCPI status system. This model consists of a condition register, a transition
filter, an event register and an enable register. A set of these registers is called a
status group.
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