OPCModbusUAServer

An open source OPC UA server for Modbus TCP devices. The project makes use of the powerful open source NodeOPCUA (http://node-opcua.github.io/) package, combined with the jsmodbus (https://github.com/Cloud-Automation/node-modbus) package to build the OPC server.

If you are not familiar with OPC, it's worth reading this: http://www.minaandrawos.com/2016/12/18/thoughts_industrial_opc/, if not familiar with Modbus, then this would be another good read: http://www.minaandrawos.com/2014/11/26/how-to-write-a-modbus-driver/#WhatIsModbus

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Main files in the project:

• server.js => The entry point for the application, creates the OPC UA server, initializes the address space, and links to Modbus actions
• modbushandler.js => Contains the Modbus communication code needed to provide Modbus actions like reads and writes for the OPC server
• config.json => Configuration file for the application, this is how we get to know the TCP addresses of the Modbus devices, the registers we'd like to read...etc

Docker container

sample modbus device using command line arguments

usage

Usage: server [options]

Options:
  -p, --port <number>                   opc ua server port number (default: 8080, env: PORT)
  -u, --url <path>                      opc ua server url-path (default: "/ModbusServer", env: URL_PATH)
  --modbus-host <host>                  specify the modbus host address (env: MODBUS_HOST)
  --modbus-port <port>                  specify the modbus tcp port (default: "502", env: MODBUS_PORT)
  --modbus-unit-id <unitId>             specify the modbus unit id (default: "1", env: MODBUS_UNITID)
  --modbus-not-onebased                 disable one based addresses
  --modbus-holdingregister [ranges...]  specify the modbus holdingregister ranges (default: [])
  --modbus-coils [ranges...]            specify the modbus coils ranges (default: [])
  --modbus-discreteinputs [ranges...]   specify the modbus discreteinputs ranges (default: [])
  --modbus-inputregisters [ranges...]   specify the modbus inputregisters ranges (default: [])
  -h, --help                            display help for command

docker run -p 8080:8080 ghcr.io/bobiene/opcmodbusuaserver:latest --modbus-host localhost --modbus-holdingregister 1:5 10 50:20

docker run -p 8080:8080 ghcr.io/bobiene/opcmodbusuaserver:latest --modbus-host localhost --modbus-holdingregister 1:5 10 --modbus-holdingregister 50:20

docker run -p 8080:8080 ghcr.io/bobiene/opcmodbusuaserver:latest --modbus-host localhost --modbus.port 503 --modbus-holdingregister 1:5 10 --modbus-discreteinputs 50:20

sample modbus device connection using config file

docker run -p 8080:8080 -v ./local.json:/usr/src/app/config/local.json ghcr.io/bobiene/opcmodbusuaserver:latest

local.json:

{
    "modbusdevices": [
        {
            "modbushost": "localhost",
            "modbusport": 8880,
            "unit": 2,
            "pollrate":500,
            "onebased":true,
            "deviceaddressspace": [
                {
                    "type": "holdingregister",
                    "addresses": [
                        {
                            "address": 1,
                            "count": 4
                        },
                        {
                            "address": 10,
                            "count": 8
                        }
                    ]
                },
                {
                    "type": "coils",
                    "addresses": [
                        {
                            "address": 1,
                            "count": 4
                        },
                        {
                            "address": 10,
                            "count": 8
                        }
                    ]
                },
                {
                    "type": "discreteinputs",
                    "addresses": [
                        {
                            "address": 1,
                            "count": 4
                        },
                        {
                            "address": 10,
                            "count": 8
                        }
                    ]
                },
                {
                    "type": "inputregisters",
                    "addresses": [
                        {
                            "address": 1,
                            "count": 4
                        },
                        {
                            "address": 10,
                            "count": 8
                        }
                    ]
                }
            ]
        }
    ]
}

Docker compose sample

git clone https://github.com/BoBiene/OPCModbusUAServer.git
cd sample
docker-compose up

use opc.tcp://localhost:8080/ModbusServer to connect to the Modbus OPC UA Server: