Feature
Today you will find other communication protocols in the built environment such as Modbus , KNX , LON as a standardised communication language that was developed and implemented into the industry over time . Having this universal open protocol created the environment where different brands would be able to be successfully installed in a single system .
The next challenge in the open protocol development was that although each brand ’ s controller would be able to communicate with another , the way in which each brand is engineered and commissioned required different programming tools and training .
In a building with ten different suppliers , this proved to be a persisting problem . This results in the technician requiring ten different engineering tool sets , and knowledge of all the different brand devices which is impractical in anyone ’ s book but remained a challenge . Therefore , for engineers and technicians alike , it became critical to be aware of device compatibility .
Today as technology has developed and gone through a process of natural evolution , controllers , for the most part , apply similar hardware interfaces ( BACnet MSTP or BACnet IP ) although some differing interpretation still occurs between brands . This has been driven primarily by the computer sector that followed a similar path , but for some time has required not only adequate communication but advanced connectivity and integration functionality .
In between the progression , product engineers had to establish new communication protocols to be able to tie devices into global networks such as MQTT and RESTful API – essentially making controllers capable of translating data into the same format of computers to be able to use this data for other processing and analysis . Long past then are the days of a simple MSTP hardwire bus , as most sectors have got to a point where IoT or 4IR has become mainstream and because better efficiency is sought out .
This conversion was achieved through JACE or EC-BOS connector boxes ( still used as default in South Africa ) that converted the controller language to standard internet protocol .
The evolution of controllers .
Analog control . Single stand-alone control loops with no programming . No graphic user interface ( GUI )
PROPRIETY PROTOCOL
STEP 1 STEP 3
STEP 2
Companies designed protocols ( languages ) to communicate over various interfaces . RS232 or RS485
This development had a significant impact onto the controller industry as advanced features became possible such as visuals and reporting , speed of data transfer rates increased , and costs were lowered .
With the latest technology and communication protocols
DDC Control - Proprietary communications . Closed system . Limited GUI . Programmable
available , if you are in the position of quoting on any automation system , there are now far more elements to consider when looking at , and understanding , the technology architecture as well as price implications of selecting cheap solutions now , versus the ability to leverage IoT / 4IR over the lifespan of the facility or plant .
The advancements of computer engineering , that has access to far more R & D funding , will no doubt continue to advance and offer many new solutions soon , but will further be driven by overarching international trends in building systems .
CONTROLLER CAPACITY As mentioned previously , all controllers exist to carry out particular functions and are highly dependent on the process application . There are different types of devices that a controller can be connected to . There are inputs and outputs that measure either analog or digital . An analog device would measures things like
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RACA Journal I September 2021 www . hvacronline . co . za