CIM networks

At the lower levels, we have a large amount of simple information that must be transferred within small and predefined deterministic time intervals. At the higher levels, the requirement is to transfer much more complex information within time intervals that do not need to be deterministic. So, in an integrated production system, different types of communication networks are required, each one specialized for the task to which it is dedicated. With regards to the CIM pyramid, we have the following networks:

• Level 1: fieldbus
• Level 2: control bus
• Levels 3, 4 and 5: corporate network

Field or fieldbus networks were introduced for interfacing control devices, sensors, and actuators, reducing the need for complex wiring. In the fieldbus, sensors and actuators are equipped with a minimum set of processing capabilities to ensure the transmission of information in a deterministic way.

Control network must ensure the communication between the devices is dedicated to the control and the supervision of the plants. In this case, the information sent is not very complex, but the transmission must occur within predefined deterministic time intervals and at higher frequencies. Control and fieldbus networks are also often called real-time networks because of their determinism in the transmission of data and information. 

Corporate network is the network channel located between the control systems and the planning and the management systems. This connectivity layer must guarantee the processing of complex information, but at low frequencies. For this reason, there is no need to have determinism on this network.