EIP Bridge

This repository contains a bridge between a ROS system and PLC using the Ethernet/IP (EIP) communication protocol.

Dependencies:

1. PyComm 1.0.8
   • pip install pycomm==1.0.8

Notes:

• Supported message types:
  • Core PLC data types (e.g. integers, floats, booleans, strings, etc.)
  • Fixed-length arrays of core PLC data types
• Not currently supported:
  • User-defined type (UDT)
  • User-defined type array
• Currently only tested on Allen Bradley PLCs

Configuration

The EIP bridge accepts a YAML config file specifying communication between the ROS system and PLC. This includes:

• Subscribers: PLC tags which should receive data from ROS topics (i.e. ROS -> PLC)
• Publishers: PLC tags which should publish their values as ROS messages (i.e. PLC -> ROS)
• Services: on-demand access via ROS service for getting/setting data of a specified type on arbitrary tags

The format of the YAML configuration file is shown below:

Services:
  - name: <Service topic name>
  - type: <Service message type>
Publishers:
  - name: <ROS topic on which to publish data>
    tag: <PLC tag from which to publish data>
    type: <PLC data type>
    length: <Array length, 0 for single values>
    sim_value: <Arbitrary value to publish for simulation>
Subscribers:
  - name: <ROS topic on which to subscribe>
    tag:  <Tag into which to write data from the ROS system>
    type: <PLC data type>
    length: <Array length (0 for single values)>
    sim_value: <Arbitrary initial value - used only by simulated PLC>

See the example configuration file for reference

Usage:

1. Create YAML file listing ROS topics to map to EIP tags

2. (Optional) Add the path to pycomm to the PYTHONPATH environment variable

   export PYTHONPATH=<path_to_pycomm_install>

   Note: this should not be necessary if pycomm was installed using pip

3. Run the launch file, specifying the path to your config file

   roslaunch eip_bridge eip_bridge.launch config_file:='/path/to/config.yaml' sim:=<true/false>