In this example, the I/O software library R&S VISA from Rohde & Schwarz is used to set up a LAN remote control link and remotely control the R&S SMC. R&S VISA is running on a controller PC with Windows operating system. When the connection is set up you can send commands to the instrument, and receive the responses.
The remote control connection requires a VISA installation but no additional hardware on the controller PC. The LAN I/O channel is selected at initialization time using the VISA resource string (also referred to as "address string"). A VISA alias (short name) is used to replace the complete resource string. The host address is either the R&S SMC's hostname or IP address. See also "LAN Interface".
![]() | In this example, it is assumed that:
|
To remote control the R&S SMC, we use the R&S VISA Tester application.
![]() | The instrument is preconfigured for networks using DHCP (dynamic host configuration protocol). If this configuration is used, enter the computer name in the position of the IP address. |
To enable the external controller to communicate with the R&S SMC via TCP/IP protocol, set up a remote control link as follows:
Make sure that the controller and the instrument are connected in the network (network cable) and switched on.
On the controller, start "R&S VISA > Tester 32bit" or "R&S VISA > Tester 64bit", respectively.
In the menu bar, select "Choose VISA Implementation > Rohde & Schwarz Visa".
Select "Rohde & Schwarz Visa" and confirm with "OK".
In the menu bar, select "Find Resource" to search for the instrument in the LAN.
Select "VXI-11" and "Find Resources".
R&S VISA scans the network for connected instruments and lists all detected instuments in the "Resource" list.
Note: The search may take some time, particularly in large networks.
Select the required instrument and confirm with "Select".
The "Find and select resource" dialog closes and R&S VISA indicates the instruments IP address in the "Resource" field of the main application window.
As an alternative to the IP address, you can assign an alias name to the R&S SMC:
In the menu bar, select "RsVisaConfig".
In the toolbar, select "+" to access the "VISA Rexource String Composer".
Fill in the "Alias" name, the "VISA Resource String" and the "Device IP Address or host name" as shown in the figure, and confirm with "OK".
The "Alias" name is assigned to the instrument.
Close the dialog.
The R&S SMC is now registered in the program and can be addressed via the resource string or alias name.
In the main window, select "Connect".
R&S VISA establishes the connection to the R&S SMC.
Now you can send settings to configure the instrument and receive its responses.
Note: If the connection cannot be set up, R&S VISA displays an error in the log view. For information on how to proceed when network failures occur, see "Resolving Network Connection Failures".
For further information on the functions to read and write to an open session, as well as the utility applications the software provides, see the R&S VISA User Manual.
To set the instrument to remote control, you can use the addressed command >R, or send any command from the controller.
Start the R&S VISA Tester and establish the connection to the R&S SMC, see "Configuring the controller".
In the R&S VISA "Basics" tab, enter a SCPI command, e.g. "*IDN?" and confirm with "Query".
The instrument is switched to remote control when it receives a command from the controller.
Select "Read" to obtain the instrument response.
Tip: If the "Show Log" checkbox is checked R&S VISA displays each VISA function call in the log-view on the left. If you check the "Write Log" checkbox the log-view entry is written to the log file as well. You can operate the log-view in two modes: the "Live Mode" shows only the most recent messages whereas the "View Mode" allows you to scroll the history.
To set, e.g. the frequency, enter SOUR1:FREQ 4 GHz and select "Write".
To check the performed setting, SOUR1:FREQ? and select "Read".
The instrument response is 4000000000, i.e. the frequency is returned in Hz.
While remote control is active, the "Remote" icon in the status bar indicates that the instrument is in remote control mode. The operation via the front panel or via mouse and keyboard are locked, allowing a remote control program to be performed without interruption.
On the display, keys and entry fields are grayed out and cannot be activated or modified, but you can still open dialogs, for example to verify settings.
To disable the access to the dialogs, use the command SYST:KLOC ON.
To prevent unintentional return to manual operation, use the command &LLO.
See also "LAN Interface Messages".
The instrument switches to "Remote LLO" state. The LOCAL key is disabled.
To enable the LOCAL key, use the command >R.
To return to manual operation, see "Returning to Manual Operation".
Tip: Switching from manual operation to remote control and vice versa does not affect the other instrument settings.
Imprint | Statement of Privacy | Terms & Conditions | © 2017 ROHDE & SCHWARZ |