Modbus Simulator

ModbusSimulator is a java based modbus protocol server simulator that can run on multiple platforms such as Windows, Linux and Macos.

How to config

• Configuration file name is config.xml
• config_sample.xml: Here's a sample that shows all of the configuration parameters you can use.

Configuration parameters

• protocolType: [MODBUS_RTU, MODBUS_ASCII, MODBUS_TCP]
• serialConnection: Serial connection configuration
  • comPort: String, COM* in windows, /dev/tty* in linux
  • baudrate: [300, 600, 1200, 2400, 4800, 9600, 14400, 19200, 38400, 56000, 57600, 115200]
  • dataBits: [7, 8]
  • stopBits: [1, 2]
  • parity: [NONE, ODD, EVEN]
• tcpConnection: TCP connection configuration
  • port: TCP Port
• modbusDataDefinition
  • slaveId: [1, 255] - Addiotional Address in modbus.
  • functionCode: [01, 02, 03, 04] - Function code in modbus.
  • address: [0, 65535] - Start address
  • quality: [1, 4096] - quality of the coils(function code 01 and 02) or register(function code 03 and 04)
  • return06Exception: [true, false] - If it's true, the response will always be 86 exception.
• modbusDataList
  • modbusData: The number of modbusData must be consistent with modbusDataDefinition.quality.
    • autoChange: [true, false] - If it's true, the statusValue will change every minute. Only works for function code 01 and 02.
    • statusValue: [on, off] - Coils value, on means 1, off means 0 in binary. Only works for function code 01 and 02.
    • random: [true, false] If it's true, the value will change randomly every minute. Only works for function code 03 and 04.
    • autoIncrement: [true, false] If it's true, the value will change add one every minute. Only works for function code 03 and 04.
    • value: [-32768, 32767] - Register value. Only works for function code 03 and 04.

How to start

Local start

• setup the config.yaml

• start the server

$ mvn clean install
$ java -jar target/ModbusSimulator.jar

• log: logs/*.log files

Docker start

• setup the config.yaml

• build docker image

$ mvn clean install
$ docker build -t modbus-simulator:v1.0 .

• start server

# Normal test
$ docker run -it --rm --name modbus-simulator modbus-simulator:v1.0

# expose the port
$ docker run -it -d -p 8888:8888 --name modbus-simulator modbus-simulator:v1.0

# mount out log files
$ mkdir ms_logs
$ docker run -it -d -p 8888:8888 -v $(pwd)/ms_logs:/app/logs --name modbus-simulator modbus-simulator:v1.0

Serial Port

Please extract following files from references/rxtx-2.2pre2-bins.zip into the $JAVA_HOME\bin folder before using the serial connection.

• rxtxSerial.dll - (for windows)
• librxtxSerial.so & librxtxParallel.so - (for linux)
• librxtxSerial.jnilib - (for mac)

Useful links

Modbus Org: https://modbus.org/

Modbus Protocol: https://www.hifreud.com/tag/#Modbus-ref

RXRX: http://rxtx.qbang.org/wiki/index.php/Download

Virtual serial port Driver: https://www.eltima.com/products/vspdxp/

Modbus Poll: https://www.modbustools.com/modbus_poll.html

Modbus Slave: https://www.modbustools.com/modbus_slave.html