What are the types of communication methods in DeviceNet?

The DeviceNet protocol is critical for ensuring seamless communication between devices in the field of industrial control systems. Understanding DeviceNet communication protocols is critical for optimizing operational efficiency. In this post, we will look at the two basic types of messages used by DeviceNet: Cyclic I/O and Explicit Message.

Communication Modes in DeviceNet:

1. Cyclic I/O:

Cyclic I/O messages in DeviceNet are synchronous and are classified based on the data exchange method. Here are the main types:

a. Change of State:

This method involves exchanging data between a master and its slave when monitored or controlled values change within a specified time limit. Transmission and reception continue uninterrupted once the time limit is reached. Flexible time variable configuration is possible using network configuration software.

b. Cyclic:

The Cyclic method, like Change of State, involves regular data interchange at set time intervals, regardless of whether the data has been modified or not. The period for this communication is set by network setup software.

c. Bit-strobe:

In this communication mode, the master delivers an 8-byte message data over the network. Each bit in these eight bytes represents an individually addressed slave that responds according to plan.

In the Cyclic I/O communication mode, the Bit-strobe method involves the master sending an 8-byte message data over the network, with each bit representing an individually addressed slave that responds as per the pre-defined plan.

d. Polled:

In Polled communication, the master sends a message to each slave in its scan list. Each slave answers quickly after hearing the request. This process is repeated until all slaves have been contacted, at which point the cycle is restarted.

2. Explicit Message:

An Explicit Message is a non-priority message type in DeviceNet that is primarily used for general reasons. It is used in asynchronous tasks, particularly in the parameterization and configuration of equipment.

Additionally, in the Explicit Message category, these messages are non-priority and find primary use in general applications, particularly in the parameterization and configuration of equipment.


Finally, the DeviceNet protocol provides two basic communication methods: cyclic I/O and explicit message. The former, using methods such as Change of State, Cyclic, Bit-strobe, and Polled, is designed for synchronous data interchange with variable priority. Explicit Messages, on the other hand, fulfill generic functions and are well-suited for asynchronous operations. Understanding these communication techniques is critical for enhancing DeviceNet in industrial settings to ensure efficient and dependable data sharing between devices.

By incorporating these insights into your industrial automation strategy, you are able to maximize DeviceNet’s potential for increased efficiency and streamlined communication.