How to Use the Command 'lxi' (with examples)

The ’lxi’ command is a powerful tool for interfacing with LXI (LAN eXtensions for Instrumentation) compatible instruments, such as oscilloscopes, function generators, and power supplies. These devices are commonly used in laboratories and industrial settings for measurement and testing purposes. By using the ’lxi’ command, users can automate data collection, control instruments remotely, and streamline the integration of these devices into broader test systems.

Developed as part of the lxi-tools project, this command line utility provides users with the ability to discover devices on a network, capture screenshots from instruments, issue commands using the SCPI (Standard Commands for Programmable Instruments) protocol, and evaluate the performance of their network communications. This command is especially valuable for engineers, researchers, and technicians who rely heavily on electronic test and measurement tools.

Use Case 1: Discover LXI Devices on Available Networks

Code:

lxi discover

Motivation:

Discovering LXI devices is a fundamental step in remotely managing and controlling them. LXI devices are network-compatible instruments that might be scattered across different networks within a facility. The lxi discover command allows a user to easily find all the connected LXI instruments, providing inventory management and making it easier to set up a testing workflow. This is especially useful in environments with numerous instruments, as manually identifying each device can be cumbersome and inefficient.

Explanation:

• lxi: This denotes the use of the LXI tools command-line interface.
• discover: This subcommand searches for all LXI-compliant devices connected to available networks. It leverages the network discovery protocols to list all accessible devices, providing essential information such as IP addresses and device IDs.

Example Output:

Discovering devices...
Device found: Rigol DS1102E at 192.168.0.10
Device found: Keysight 34461A at 192.168.0.11

Use Case 2: Capture a Screenshot, Detecting a Plugin Automatically

Code:

lxi screenshot --address 192.168.0.10

Motivation:

Capturing screenshots from instruments like oscilloscopes with display outputs allows users to document experimental results and share findings with colleagues. Using this command, users can retrieve visual data directly from devices without needing physical access, streamlining remote work and collaborative research. This simplifies the process of monitoring ongoing experiments, validating results, and archiving observations.

Explanation:

• lxi: Initiates the LXI tools command.
• screenshot: This subcommand is used to retrieve a screenshot from the device.
• --address 192.168.0.10: Specifies the IP address of the device from which the screenshot will be taken. The system will automatically detect which plugin to use based on the device’s details.

Example Output:

Screenshot captured and saved as 2023-11-01_oscilloscope.png

Use Case 3: Capture a Screenshot Using a Specified Plugin

Code:

lxi screenshot --address 192.168.0.10 --plugin rigol-1000z

Motivation:

Certain devices may require specific plugins to correctly interpret and interact with, particularly when automatic detection fails or is inaccurate. By manually specifying a plugin, users can ensure that the screenshot functionality operates as expected, avoiding compatibility issues. This is crucial in environments where non-standard or older devices are in use, which may not conform to more recent detection protocols.

Explanation:

• lxi: Initiates the command utility for LXI tools.
• screenshot: Requests a screenshot from the designated instrument.
• --address 192.168.0.10: Indicates the target device’s IP address.
• --plugin rigol-1000z: Directs the command to employ the ‘rigol-1000z’ plugin, ensuring compatibility with specific models of Rigol oscilloscopes for accurate screen capture.

Example Output:

Screenshot captured and saved as 2023-11-01_rigol.png

Use Case 4: Send an SCPI Command to an Instrument

Code:

lxi scpi --address 192.168.0.10 "*IDN?"

Motivation:

SCPI commands form the backbone of automated instrument control. Sending SCPI commands to devices enables precise configuration, operation, and data retrieval remotely, critical for automated testing systems where minimizing human intervention is paramount. For example, querying the identification string with “*IDN?” helps verify that the correct device is configured and provides device-specific information for logging and analysis.

Explanation:

• lxi: Starts the use of the LXI tools command.
• scpi: The subcommand for sending SCPI commands to the instrument.
• --address 192.168.0.10: Specifies the IP address of the targeted device.
• "*IDN?": This SCPI command requests the instrument’s identification string, providing device description details like manufacturer name and serial number.

Example Output:

Response: Rigol Technologies,DS1102E,DS1ED141123456,04.05

Use Case 5: Run a Benchmark for Request and Response Performance

Code:

lxi benchmark --address 192.168.0.10

Motivation:

Running a benchmark test on an instrument’s network communication capabilities can help diagnose and troubleshoot connectivity issues, ensuring efficient and reliable data transfer between the device and the controlling system. By assessing performance metrics such as request-response time, the benchmark helps identify bottlenecks or weaknesses in the setup, aiding in improving system robustness and reliability.

Explanation:

• lxi: Invokes the LXI tools interface.
• benchmark: This subcommand runs a performance evaluation test to measure how efficiently the system can send requests to and receive responses from the specified device.
• --address 192.168.0.10: Identifies the device’s IP address subjected to the benchmark testing.

Example Output:

Benchmark test started...
Requests: 100 | Average Response Time: 10ms | Packet Loss: 0%

Conclusion:

The ’lxi’ command provides a comprehensive set of utilities for managing LXI-compatible devices, empowering users with efficient remote control capabilities. From device discovery to performance benchmarking, it allows seamless integration of instrumentation into automated systems, thereby enhancing productivity and reducing operational overheads. Through these examples, professionals can better harness the power of lxi tools to optimize their workflows, troubleshoot issues, and manage test systems effectively.