Protocols Overview

Protocols are the communication languages spoken by control devices. The main purpose of a protocol is to communicate information in the most efficient method possible. Different protocols exist to provide different kinds of information for different applications.


In the BAS application, many different protocols are used, depending on the manufacturer. More and more owners are demanding that their entire facilities be seamlessly linked together and presented in one easy-to-use front end.


All of our translators have the ability to speak multiple protocols. So, no matter what company your customer chooses for the controls in the rest of their building, our translator will communicate with them without the added cost of a gateway.

 

What is a protocol?


• A set of formal rules describing how to transmit data, especially across a network
• A low level protocol defines:
the electrical and physical standards to be observed
bit-and-byte-ordering
the transmission, error detection, and correction of the bit stream
• A high level protocol deals with data formatting, including:
syntax of messages
terminal-to-computer dialogue
character sets
sequencing of messages, etc.
• It is a language spoken between electronic devices


NOTE An example is the protocol IP, which stands for Internet Protocol
For two devices to communicate with each other, they must speak the same protocol or have a protocol translator.

 

Why are there so many protocols?


• Because any two pieces of building automation equipment can vary with application, so can the protocol
• Due to varying applications, protocols are designed with efficiency in mind

 

What are the most common protocols in building automation systems?


The four most common protocols in the building automation industry are:

BACnet

Modbus

N2 (N2 Open)

LonWorks

 

What are the benefits of having four of the most widely used protocols built in?


• Manufacturers can now provide a translator with their units that can be seamlessly integrated into a BAS
• For the building owner, it means upgrade and expansion costs will be competitive
• Expensive gateways are eliminated
• Field selection of the protocol requires less up-front coordination, thus reducing manufacturing costs
• Flexibility and simple configuration allow the customer to make future additions and changes without additional costs
• More opportunities for sales