End of support notice: On October 7th, 2026, AWS will discontinue support for AWS IoT Greengrass Version 1. After October 7th, 2026, you will no longer be able to access the AWS IoT Greengrass V1 resources. For more information, please visit Migrate from AWS IoT Greengrass Version 1.

Modbus-TCP Protocol Adapter connector

The Modbus-TCP Protocol Adapter connector collects data from local devices through the ModbusTCP protocol and publishes it to the selected StreamManager streams.

You can also use this connector with the IoT SiteWise connector and your IoT SiteWise gateway. Your gateway must supply the configuration for the connector. For more information, see Configure a Modbus TCP source in the IoT SiteWise user guide.

This connector has the following versions.

For information about version changes, see the Changelog.

Requirements

This connector has the following requirements:

Version 1 - 3

• AWS IoT Greengrass Core software v1.10.2 or later.

• Stream manager enabled on the AWS IoT Greengrass group.

• Java 8 installed on the core device and added to the PATH environment variable.

Note

This connector is only available in the following regions:

• ap-southeast-1

• ap-southeast-2

• eu-central-1

• eu-west-1

• us-east-1

• us-west-2

• cn-north-1

Connector Parameters

This connector supports the following parameters:

The following is an example of a CapabilityConfiguration:

{
    "sources": [
        {
            "type": "ModBusTCPSource",
            "name": "SourceName1",
            "measurementDataStreamPrefix": "SourceName1_Prefix",
            "destination": {
                "type": "StreamManager",
                "streamName": "SiteWise_Stream_1",
                "streamBufferSize": 8
            },
            "endpoint": {
                "ipAddress": "127.0.0.1",
                "port": 8081,
                "unitId": 1
            },
            "propertyGroups": [
                {
                    "name": "GroupName",
                    "tagPathDefinitions": [
                        {
                            "type": "ModBusTCPAddress",
                            "tag": "TT-001",
                            "address": "30001",
                            "size": 2,
                            "srcDataType": "float",
                            "transformation": "byteWordSwap",
                            "dstDataType": "double"
                        }
                    ],
                    "scanMode": {
                        "type": "POLL",
                        "rate": 100
                    }
                }
            ]
        }
    ]
}
            

Create Connector Example (AWS CLI)

The following CLI command creates a ConnectorDefinition with an initial version that contains the Modbus-TCP Protocol Adapter connector.

aws greengrass create-connector-definition --name MyGreengrassConnectors --initial-version '
{
    "Connectors": [
        {
            "Id": "MyModbusTCPConnector",
            "ConnectorArn": "arn:aws:greengrass:region::/connectors/ModbusTCP/versions/3",
            "Parameters": {
                "capability_configuration": "{\"version\":1,\"namespace\":\"iotsitewise:modbuscollector:1\",\"configuration\":\"{\"sources\":[{\"type\":\"ModBusTCPSource\",\"name\":\"SourceName1\",\"measurementDataStreamPrefix\":\"\",\"endpoint\":{\"ipAddress\":\"127.0.0.1\",\"port\":8081,\"unitId\":1},\"propertyGroups\":[{\"name\":\"PropertyGroupName\",\"tagPathDefinitions\":[{\"type\":\"ModBusTCPAddress\",\"tag\":\"TT-001\",\"address\":\"30001\",\"size\":2,\"srcDataType\":\"hexdump\",\"transformation\":\"noSwap\",\"dstDataType\":\"string\"}],\"scanMode\":{\"rate\":200,\"type\":\"POLL\"}}],\"destination\":{\"type\":\"StreamManager\",\"streamName\":\"SiteWise_Stream\",\"streamBufferSize\":10},\"minimumInterRequestDuration\":200}]}\"}"
            }
        }
    ]
}'

Input data

This connector doesn't accept MQTT messages as input data.

Output data

This connector publishes data to StreamManager. You must configure the destination message stream. The output messages are of the following structure:

{
    "alias": "string",
    "messages": [
        {
            "name": "string",
            "value": boolean|double|integer|string,
            "timestamp": number,
            "quality": "string"
        }
    ]
}

Licenses

The Modbus-TCP Protocol Adapter connector includes the following third-party software/licensing:

This connector is released under the Greengrass Core Software License Agreement.

Changelog

The following table describes the changes in each version of the connector.

A Greengrass group can contain only one version of the connector at a time. For information about upgrading a connector version, see Upgrading connector versions.

See also