The following diagram a simple block diagram representation of ROS-I packages, which are organized on top of ROS. We can see the ROS-I layer on top of the ROS layers. We can see a brief description of each of the layers for better understanding. The following diagram is taken from ROS-I wiki page (http://wiki.ros.org/Industrial).

• The ROS GUI: This layer includes the ROS plugin-based GUI tools layer, which consists of tools such as RViz, rqt_gui, and so on
• The ROS-I GUI: These GUIs are standard industrial UI for working with industrial robots which may be implemented in the future
• The ROS Layer: This is the base layer in which all communications are taking place
• The MoveIt! Layer: The MoveIt! layer provides a direct solution to industrial manipulators in planning, kinematics, and pick and place
• The ROS-I Application Layer: This layer consists of an industrial process planner, which is used to plan what is to be manufactured, how it will be manufactured, and what resources are needed for the manufacturing process
• The ROS-I Interface Layer: This layer consists of the industrial robot
  client, which can connect to the industrial robot controller using the simple message protocol
• The ROS-I- Simple Message Layer: This is the communication layer of the industrial robot, which is a standard set of protocol that will send data from the robot client to the controller and vice versa.
• The ROS-I Controller Layer: This layer has vendor-specific industrial robot controllers.

After discussing the basic concepts, we can start working on interfacing an industrial robot to ROS using ROS-I. The following are the major issues we need to address:

• How to create a URDF model for an industrial manipulator?
• How to create MoveIt! interface for an industrial manipulator?
• What are industrial robot driver packages?
• What are support packages in ROS-I and how are created?
• How to create IKFast MoveIt! plugins for Industrial robots?

We can see each issue and its solutions with an example