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Modbus Client Action

The Modbus Client action in Machinechat JEDI enables you to efficiently communicate with Modbus devices for data acquisition and control. This action supports both read and write operations, allowing for comprehensive interaction with Modbus-enabled hardware.

Key Features:

  • Read and Write Capabilities: Seamlessly read data from and write data to Modbus devices.
  • Multiple Operations: Add one or more read and write operations to a single Modbus Client action.
  • Modbus Read Operation: Configure operations to retrieve data from specific registers in the Modbus device.
  • Modbus Write Operation: Set up operations to send data to specific registers in the Modbus device.

Configuring Modbus Client Action

The Modbus Client action allows you to set up connection with your Modbus devices and perform read and write operations. JEDI's Modbus Client action supports Modbus-TCP and Modbus-RTU (Serial/RS485).

Modbus Client Action Settings
Modbus Client Action Settings

Modbus-TCP Configuration

This section guides you through configuring the Modbus Client action for communicating with Modbus-TCP devices.

Modbus Client Action TCP Settings
Modbus Client Action Modbus-TCP Settings

  • Action Name: Enter a name for this action. This name helps in quickly recognizing and managing actions within your rules.

  • Action Type: Select the action type. In this case, it is "Modbus Client".

  • Source/Destination Node ID: Enter the Node ID of the metric that will be used to store data from the operations in this action. This is the Node ID part of the node.metric pair used in JEDI's data storage.

  • Slave ID: Enter the Slave ID of the Modbus device for this action. This ID is used to address the specific device on the Modbus network.

  • Connection Type: Select between TCP (over network) and RTU (over serial/RS485). In this form, TCP is selected.

  • Modbus Server Hostname or IP: Enter the hostname or IP address of the Modbus-TCP device. This field specifies where the Modbus client should connect.

  • Port: Optionally, enter the TCP port number of the Modbus-TCP device. The default port for most Modbus devices is 502. If the Modbus device uses a different TCP port, enter the appropriate port number here.

  • Timeout: Enter the timeout value to use for operations that are part of this action. This specifies how long JEDI should wait before considering the operation as failed.

  • Operations: This section lists the Modbus read and write operations associated with this action. The + button allows you to add operations to this action.

Modbus-RTU Configuration

This section guides you through configuring the Modbus Client action for communicating with Modbus-RTU devices.

Modbus Client Action RTU Settings
Modbus Client Action Modbus-RTU Settings

  • Action Name: Enter a name for this action. This name helps in quickly recognizing and managing actions within your rules.

  • Action Type: Select the action type. In this case, it is "Modbus Client".

  • Source/Destination Node ID: Enter the Node ID of the metric that will be used to store data from the operations in this action. This is the Node ID part of the node.metric pair used in JEDI's data storage.

  • Slave ID: Enter the Slave ID of the Modbus device for this action. This ID is used to address the specific device on the Modbus network.

  • Connection Type: Select between TCP (over network) and RTU (over serial/RS485). In this form, RTU is selected.

  • Device: Select the serial interface from the list of serial interfaces discovered on this computer.

  • Data Bits: Select the number of data bits for the selected serial interface.

  • Stop Bits: Select the number of stop bits for the selected serial interface.

  • Parity: Select the parity for the serial selected interface.

  • Timeout: Set the duration, in seconds, for the operation to wait for a response from the Modbus device before timing out. This specifies how long JEDI should wait before considering the operation as failed.

  • Operations: The read and write operations to be performed by this Modbus Client action. Each Modbus Client action can include multiple read and write operations. Ensure not to create circular dependency loops with the operations.

Supported Modbus Operations

The following Modbus operations are supported by Modbus Client* action.

Supported Modbus Operations
Supported Modbus Operations

Setting Up a Modbus Operation

This section guides you through adding a Modbus operation to the Modbus Client action.

Modbus Operation
Modbus Operation

The Modbus Operation Configuration form allows you to add and configure various Modbus operations within the Modbus Client action in Machinechat JEDI.

  • Source/Destination Metric: Enter the name of the metric to use for this operation. This is the metric part of the node.metric pair.

  • Address: The Modbus register address for this operation. Refer to the Modbus device documentation to find the correct register address.

  • Operation: Select a Modbus operation from the list. Supported operations include:

  • "Read Discrete Inputs"
  • "Read Input Register"
  • "Read Holding Register"

  • "Write Register"

  • Value Type: Select a datatype for this operation. Supported datatypes are:

    • Byte
    • Word
    • Short
    • Long
    • BCD
    • LBCD
    • Float

  • Value or Expression: Optionally specify a value to use for this operation or provide an expression to transform the data. The example in the screenshot shows a Celsius to Fahrenheit conversion expression: ((9.0/5.0) * Temperature) + 32.0.

  • Set Precision: Optionally set the precision for the result of the operation. Check the box to enable precision setting and specify the number of decimal places.

  • Force Modbus Little Endian (non-standard): Some Modbus devices require a different endianness setting. Check this box to force the use of Little Endian format, which is a non-standard setting for Modbus.

  • ADD: Click the ADD button to add the operation to the Modbus Client action.

Need help? Contact our support team support@machinechat.io