Project Design : we want to create a Programmable Logic Controllers(PLC) set with 2 PLCs to below tasks:
-
Read the 10 trains speed sensors (connect to PLCs' input) from the real-word emulator to PLCs' holding register state.
-
Use 10 PLC output coils to control the trains power.
-
Create a Modbus server to handle the HMI's Modbus TCP request to update/change register/coils value.
This simulator will simulate 2 standard Siemens S71200 PLCs (16 input + 8 output / total 32 input + 16 output) PLCs connected under master and salve mode with rs422 multi-drop cable as below:
So the Trains Controller HMI can control 2 PLCs' state by connecting master PLC's ip address through Modbus TCP protocol.
[TOC]
Railway Trains Sensor-Signal System Control PLC Simulator is part of the Railway IT/OT System security test platform. It is used to control the trains' operation process in the railway system. You can refer the system topology diagram to check its function in the system by below link:
- Railway IT/OT System security test platform system structure diagram
- Railway IT/OT System security test platform network topology diagram
Two PLC (PLC-06, PLC-07) are involved in this program, PLC-06 is the master and PLC-07 is the salve. This program is used to control the railway's station system. There will be 10 input and 10 output and 0 ladder logic in this PLC set.
Each trains' speed sensor will send its state to PLC and PLC will control the trains' power state:
Program version: v0.1.2
Code base: https://github.com/LiuYuancheng/Metro_emulator/tree/main/src/plcCtrl/trainPlcEmu
The program contents 2 main thread :
- Real-world communication thread to fetch train speed sensors data and set train power state.
- Modbus server thread to handling the Modbus TCP request from Train Controller HMI.
This is the program modules workflow diagram:
The system contents 19 ladder logic which shown in the introduction. The PLC input => Holding register => ladder logic => Coil => PLC output map is shown below:
You can also check the excel file ladderConnectionMap.xlsx to see the mapping detail.
| Idx | Program File | Execution Env | Description |
|---|---|---|---|
| 1 | trainPlcEmu/plcConfig.txt | System config file. | |
| 2 | trainPlcEmu/plcSimGlobalTrain.py | python 3 | System needs global file, the system config file's contents will be saved in the global parameters. |
| 3 | trainPlcEmu/plcSimulatorTrain.py | python 3 | Main PLC simulation program. |
Libraries required code base: https://github.com/LiuYuancheng/Metro_emulator/tree/main/src/lib
- pyModbusTCP : https://github.com/sourceperl/pyModbusTCP
pip install pyModbusTCP
OS : ubuntu 20.04 server
Display mode:
- Display output: No
VM Deploy Config:
- NIC number: 2
- SSH: enable
- NIC 1: IP address: 10.0.10.13, gateway: 10.0.10.1
- NIC 2: IP address: 192.168.100.13, gateway: 192.168.100.1
Open config file plcConfig.txt
# This is the config file template for the module <monitorApp.py>
# Setup the paramter with below format (every line follow <key>:<val> format, the
# key can not be changed):
# Set the master PLC's name
PLC_NAME:PLC-06
# Define the ip addresses allowed to read PLC state:
# json list fomat: ["masterIP", "slave1IP", ...]
ALLOW_R_L:["127.0.0.1", "192.168.0.10"]
# Define the ip addresses allowed to change PLC state:
# json list fomat: ["masterIP", "slave1IP", ...]
ALLOW_W_L:["127.0.0.1"]
# Define Realworld emulator ip
RW_IP:127.0.0.1
# Define Realworld emulator connection port
RW_PORT:3001
# Define PLC clock interval
CLK_INT:0.9
# Define modbus TCP host IP, use 0.0.0.0 or localhost
MD_BUS_IP:localhost
# Define modbus TCP host Port, normally use 502
MD_BUS_PORT:504
After follow the instruction in the file metroConfig.txt to setup all the parameters, you can run the program:
python plcSimulatorTrain.py
or double click the file runTrainPlcCtrlEmu.bat
Refer to doc/ProblemAndSolution.md
last edit by LiuYuancheng ([email protected]) by 26/07/2023 if you have any problem, please send me a message.