External Multiport Test Set Control

Test sets are designed to be controlled by the PNA/PNA-X.. There is a switch matrix that is controlled over GPIB/LAN/USB interface. They are independent instruments and do not require the PNA/PNA-X.

The PNA-X with a test set controlled over the test set interface can run in either multiport VNA or standalone VNA mode.

You need to run in multiport VNA mode with option 551. You cannot use any application measurement class in this mode.

If you want to use an application measurement class with a test set, you need to run in standalone mode. The PNA-X does not know the presence of the test set in this mode, and you can use any application measurement classes. You can send a SCPI command to the PNA-X to set the switch position to the desired RF path in the test set.

The switch matrix controlled over GPIB/LAN/USB interface cannot be used to make N-port S-parameters. You need to control these test sets independently from PNA’s measurements.

Other System Configuration Topics

Supported Test Sets

The list of test sets that provide integrated solutions with the PNA is constantly growing. For a current list of supported multiport test sets, see www.Keysight.com/find/multiport

Option 551

Option 550 is no longer available.

Note: By default, the system logical test ports are mapped as follows:

  • Port 1 - PNA port 1

  • Port 2 - Test Set port 2

  • Port 3 - PNA port 2

  • Port 4 - Test Set port 4

The ports can be remapped using the Port Control Setting.

Block Diagram of a 2-port PNA and N44xx Test Set

Click one of the S-parameters to see switch and path changes. Because the test set does NOT contain receivers, measurement speed and calibration can be affected.

Procedure - How to enable full Multiport Capability

  1. Enable Option 551.

  2. Connect the test set to the PNA using the documentation that was shipped with the test set.

  3. Restart as Multiport PNA

  4. Make optional External Test Set Control Settings

Connect and Configure the Test Set

Connect the test set to the PNA using the test set documentation. Most test set documentation can found at www.Keysight.com

Test Set I/O-controlled test sets

Test sets that are controlled using the Test Set I/O connector have NO return communication capability. The PNA sends commands out the rear panel connector. It is assumed that the test set is responding appropriately. The "Active" LED, located on the test set front panel, should light when the test set is addressed in Multiport Mode or manual operation. When the test set is not in use, the Active LED will be OFF.

GPIB-controlled test sets

Connect the test set to the GPIB using one of the following methods:

Restart as Multiport PNA

How to Enable Multiport capability

Note: If Option 551 has not been enabled, the following Multiport Capability menu selection will NOT be available.

Using front-panel
[softkey] buttons

Using a mouse with PNA Menus

  1. Press System

  2. then [Configure]

  3. then [Multiport Capability]

  1. Click Utility

  2. then System

  3. then Configure

  4. then Multiport Capability


Multiport Restart dialog box help

See Also External Test Set Control and other PNA Functions

After the test set is connected and PNA Option 551 is enabled, the following settings are used to enable Multiport operation.

Test Set  Select the test set file to load.  Only the files that are appropriate for use on that PNA model are displayed.

To Add a new Test Set file:

  1. On the PNA, click File, then Exit to quit the PNA application.

  2. Download the Test Set file from: http://na.support.keysight.com/multiport/testsets/

  3. Save it to the PNA c:\users\public\network analyzer\testsets

  4. Start the PNA application.

  5. Click Utility, then System, then Configure, then Multiport Capability.

  6. In the Multiport Restart dialog, click Restart as multiport PNA with this testset.

  7. The new test set should now be visible from the Testset: menu.

Address  Enter the test set address if the test set is connected to GPIB. Connections over the Test Set I/O connector are determined by their sequence.

  • Restart as a standalone PNA.  The PNA shuts down and restarts as a standard PNA.  If the test set is left connected to the PNA, switch the test set OFF, then back ON to ensure that the test set routes signals to ports 1 and 2 of the PNA.  In this condition, there is more loss in the test paths than without a test set connected. If the power switch is OFF, there is SIGNIFICANTLY more loss in the test paths.

  • Restart as a multiport PNA with this testset. The PNA shuts down and restarts as a multiport PNA with the selected test set.

Click OK  The PNA shuts down and restarts in the selected configuration.

To learn how to change port mapping, see Port Control.


If the PNA cannot find the test set, the following error is displayed on the PNA:

GPIB ERROR Address xx cannot open VISA session.

To correct the problem, verify the following:

Important: After the problem has been fixed:

  1. On the External Test Set Control dialog, click Enable Test Set Control.

  2. Restart Triggering - click Sweep, Trigger, Continuous.

  3. The PNA again tries to find the test set.

External Test Set Control Settings

The following External Test Set Control Settings are used to configure Multiport test sets. For the N44xx test sets, the only setting that is necessary is port control.

How to access the External Test Set Control Settings

Using front-panel
[softkey] buttons

Using a mouse with PNA Menus

  1. Press trace/chan

  2. then [Channel]

  3. then [Hardware Setup]

  4. then [External Testset]

  5. then [Other External Test Sets]

  1. Click Trace/Chan

  2. then Channel

  3. then Hardware Setup

  4. then External Testset

  5. then Other


External Test Set Control dialog box help

Important Notes:

Select ID  

  • For N44xx test sets: the GPIB address

  • For other Multiport test sets: either GPIB address or 0 for Test Set I/O controlled test sets.

Enable Test Set Control  When cleared, port switching and control line settings are disabled. This selection affects all channels using the selected test set. When checked, the 'Show Test Set Properties' checkbox is also checked automatically.

Load Test Set File  For operating without Option 551.

If your Test Set is not visible, see Add a new Test Set.

The selected test set file is loaded.

  1. Navigate to the folder: C:/Program Files(x86)/Keysight/Network Analyzer/testsets/

  2. Select a test set control file.

The title of the dialog shows the model of the test set file that is currently loaded.

See a list of supported test sets.

Show Test Set Properties  This box becomes checked by default when the Enable Test Set Control is checked. When checked, a second row on the status bar appears which indicates the test set that is being controlled and the current port control selection.  For example, the following image shows the status bar when controlling an E5091A test set and a Z5623A K64 test set:

  1. Configured channel

  2. Port Control settings for E5091A

  3. Port Control settings for Z5623A K64

  4. Test Set Label. This field is shared between Interface Control and External Test Set Control. The two labels are separated by /.

Control of the second status bar is completely separate from the first status bar, which is controlled from the View, Status Bar menu.

Test Set Label  NOT available with option 551. Add text to appear on the second status bar when Show Test Set Properties is checked. See image above.

Port Control  Controls mapping of Physical ports to Logical ports. (Refer to image of dialog box above.)

  • Physical ports are the port numbers that are labeled on the test set front panel.

  • Logical ports are the port numbers that are referred to by most of the PNA application prompts and dialog boxes.

Port Mapping Notes

  • Port Control and Control Line settings effect the channel of the active (selected) measurement. These settings occur as the channel is being measured.

  • Correction is turned OFF when port mappings are changed.

  • After the physical ports are mapped to logical ports, all PNA references to port numbers refer to LOGICAL port numbers. The only exception to this is during calibrations.

Control Lines  For use with the U30xxA test sets.  Specifies the values of individual control lines. These general purpose control lines on the test set front-panel can be used in your test setup. Each button toggles the control line HIGH and LOW. When first opened, the selections reflect the current control lines. See your test set documentation for more information about the control lines.

OK   When clicked, the changes to the dialog box are implemented and the port selections and control values are immediately sent to the specified test set. The Port Control and Control line settings are stored with other channel data and used when those channels are swept.

Cancel  (or Escape) Changes to the dialog are not implemented and revert to the settings before the dialog box was opened.

External Test Sets and other PNA Functions

The following features may work differently with a test set connected to the PNA.

Remote Commands

Sweep Settings

To compensate for additional cable lengths:

Interface Control

When both Interface Control and External Test Set Control are configured, the commands on the Interface Control Before Sweep Start tab are sent out before any External Test Set Control commands are executed on that channel. Similarly, commands on the After Sweep End tab are sent after Test Set Control commands.


With an External Test Set connected, calibration is performed exactly like a PNA with the following exceptions:

Source Power Cal

Source power calibration involves adjusting the source so that the power at an output port is flat across a frequency range. Because of additional loss through some of the test set paths, it may NOT be possible to obtain corrected output power because of limitations on the source signal.

During a Source Power Cal, you are prompted when and where to connect the power sensor. When one of the supported test sets are connected, the prompt refers to the PHYSICAL port number, NOT the LOGICAL port number. To help with translating physical to logical port mappings, enable Show Test Set Properties.

Measurements with Shared Receivers

External test sets do not contain receivers. The PNA receivers are always used to measure signals at the external test set ports. Therefore, when a channel contains two measurements that share a PNA test port receiver, additional sweeps are necessary.

For example, to make S34 and S44 measurements in the same channel with correction OFF:

Create Ratioed and Unratioed Measurements

When using an external test set, it IS possible to create a Ratioed measurement using two logical receivers that share the same physical PNA receiver. However, this measurement data is NOT valid. Invalid measurement traces show all data at -200 dB (in Log mag format). Learn about Logical Receiver Notation

Logical Port References

When an external test set is enabled, all references to PNA port numbers and test set port numbers (except during calibrations) refer to LOGICAL port numbers. Logical ports can be remapped using the Port Control settings. During a calibration, you are prompted to connect standards to physical port numbers.

Balanced Port Mapping

"Logical Ports" is a term that is used with both External Test Sets and balanced measurements. While the concept is the same, they refer to different scenarios. The two can be easily confused when making Balanced measurements with an External Test Set connected. The important principle to remember is the order in which the logical ports for each are mapped:

  1. In the External Test Set - Port Control settings dialog, the physical PNA ports and test set ports are mapped to logical ports as noted above.

  2. In the Balanced Topology Dialog, the new (step 1) logical ports are mapped again to become Balanced logical ports.

1. External Test Set Mapping Dialog

2. Balanced Topology Dialog


Instrument Preset will reset Port Control settings to defaults and remove the test set label. All other settings remain. To maintain port control settings and the test set label, create a User Preset.

Instrument State Save and Recall

Instrument State files include Test Set model, Enable and Status bar settings, and Port mappings and DUT control values for each channel.

If an Instrument State recall requires that a test set configuration file be loaded, recall time may be significant. For example, this would occur if a 2-port PNA with attached test set is configured as a 2-port PNA and then recalls a state file which requires 4-port operation.

Recall Cal Sets

If a Cal Set is saved while an external test set is enabled, when the Cal Set is recalled, then the external test set must be enabled or an error message is displayed.

Copy Channel

Copy Channel copies all relevant test set data from the source channel to the target channel.


No PNA applications are supported with External Test Set Control. These include FCA (opt 083), SMC (opt 082), GCA (opt 086), NFA (opt 029), Pulsed (opt H08).


Port mapping information appears on the Channel Settings Table when printing.

Save sNp Files

To save sNp data with an external test set enabled, click File, Save As, then select Snp File(*.s*p), then complete the Choose ports dialog.