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Modbus RTU Sniffer

A Modbus RTU sniffer is a tool used to monitor and analyze communication on a Modbus RTU network. This type of software or device allows you to intercept and record the Modbus messages exchanged between master and slave devices on the network. Here’s a detailed description of how it works and how it can be used:

What is Modbus RTU?

Modbus RTU (Remote Terminal Unit) is a communication protocol used in industrial automation for data transmission between devices. It is a version of the Modbus protocol that uses serial communication, typically over RS-485 or RS-232.

Functions of a Modbus RTU Sniffer

  1. Capture Data: It intercepts and captures all Modbus RTU frames transmitted over the network. This includes requests from the master and responses from the slave devices.
  2. Analyze Communication: It provides tools to analyze the captured data, including decoding the Modbus frames, displaying the data in a human-readable format, and highlighting any communication errors or anomalies.
  3. Debugging: It helps in debugging and troubleshooting Modbus RTU communication issues by allowing you to see exactly what data is being sent and received.
  4. Performance Monitoring: It can be used to monitor the performance of the Modbus RTU network, identifying issues such as high latency, frequent communication errors, or device malfunctions.
  5. Security Auditing: It assists in security auditing by detecting unauthorized devices or suspicious communication patterns on the network.

How to Use a Modbus RTU Sniffer

  1. Setup: Connect the sniffer device to the Modbus RTU network. This typically involves connecting to the RS-485 or RS-232 bus.
  2. Configuration: Configure the sniffer software to match the network settings, such as baud rate, parity, and stop bits.
  3. Capture Data: Start capturing the Modbus RTU traffic. The sniffer will record all data exchanged on the network.
  4. Analyze Data: Use the sniffer’s analysis tools to examine the captured data. Look for specific Modbus frames, analyze communication patterns, and identify any errors or anomalies.
  5. Report Findings: Generate reports based on the analysis. These reports can be used for debugging, performance optimization, or security auditing.

Popular Modbus RTU Sniffer Tools

  • Wireshark: A widely used network protocol analyzer that supports Modbus RTU with appropriate dissectors.
  • Modbus Doctor: A specialized tool for diagnosing and troubleshooting Modbus communication.
  • CAS Modbus Scanner: A Modbus RTU and TCP/IP communication diagnostic tool.

Using a Modbus RTU sniffer can greatly enhance your ability to maintain and troubleshoot Modbus RTU networks, ensuring reliable and efficient communication between your industrial devices.

ANC-100e Ethernet IP to AB's DH+ Converter

The Automation Networks ANC-100e communicates with all SCADA, HMI, PLC programming with direct Ethernet/IP access to the DH+ network and stations. 

ANC-100e has similar replacement features as the Controllogix 1756-DHRIO / 1756-ENBT, and AB 1784 Interface Cards: 1784-U2DHP, 1784-KTx, 1784-PKTx, 1784-PCMK and Prosoft AN-X2-DHRIO Converters.

$1,295 USD List. Apr 1, 2024

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ANC-120e USB to AB's DH+

The ANC-120e is an economical and high performance USB-to-Allen-Bradley Data Highway Plus converter interfacing major HMI, SCADA, PLC Programming packages to Devices on DH+. Its features significantly outperform AB’s 1784-U2DHP PLC Programming Cable operating at 12 Mg USB speed with the Controllogix Ethernet/IP Driver.

The ANC-120e works with all SCADA, MMI, PLC programming packages installed on your PC with USB direct access to the DH+ network and stations. These packages include RSLINX/LOGIX Classic & Enterprise with RSLOGIX 5/500, Wonderware DAServer & TCP/IO Server, Citect, and Kepware using Controllogix Ethernet/IP Drivers. 

$995 USD List. Apr 1, 2024

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