I remember designing generator control systems with control relays and pneumatic timers. The number of control relays was in proportion to the complexity of the functionality required for the system. In some applications, just to house the control system, there was a suite of full height control panels. If you opened the panel doors in the dark, it used to look like Christmas with all the little flashes from the relay contacts. It took considerable effort to test and commission the systems and this was regarded as normal. Any modification of the control system required re-wiring circuits and either adding or deleting control relays and timers.
A few of the sequences were automatic but the functions were initiated by an operator. This meant that the systems required operators to be in attendance. Many operators were distrustful of the control system, with its maze of circuits, relays and timers. Consequently, some sort of manual “over-ride” switch had to be provided, which could be used by the operator in an “emergency” if the control system failed.
There had to be a better way to design and build a control system! This happened one day when PLCs came on the market. The number of control relays and timers could be reduced because the logic functions were performed in the PLC. We used PLCs with 256 addresses of memory and learnt new terms like “input” and “output”. The size of the control panels was reduced in proportion to the number of relays and timers that were replaced by the PLC. The functionality of the systems and the number of sequences which could be automated increased. Gradually, the system automation meant that many tasks no longer needed an operator.
Design drawings were done on computers instead of tracing paper and ink. New design tools were developed such as AutoCAD. We started to use photocopier and facsimile machines. Everyone was worried about losing their job because of computers.
But some things did not change, it was still required to provide some sort of manual “over-ride”. I saw one site which used PLCs to operate the entire plant. The PLCs were neatly housed in a suite of control panels. However, the wall behind the operator’s control desk was full of manual / auto switches from the roof to the floor. There would have been over one hundred switches.
You could see the look of fear in the operator’s eyes. They were terrified of ever having to manually control the plant! The fear was for a number of reasons. Firstly they didn’t have the in-depth understanding of the plant processes to be confident in manually operating equipment. Secondly, even if they did have the knowledge, they were worried that they may have forgotten some aspects because they did not use the knowledge very often. This got worse over time as new operators came on board. Thirdly, it was possible they would be held responsible if they switched the wrong device and caused an outage in the plant or maybe damaged some equipment.
The challenge for the operator was to have good training. The solution was to automate more of the systems and processes. This happened with the advent of SCADA and HMIs. At the same time there was a massive change in devices from electro-mechanical to solid state types. The systems communicated data over “buses”.
Then came a new communication tool called the “InterNet” and the world wide web. We started to use Emails.
Again we learnt new terms like “ModBus”, “FieldBus”, “DNP”, “Wifi” and “EtherNet”. We had to learn about interfacing different protocols. Testing and commissioning were now more about the software and less about the hardware. However, some things did not change. There was the same requirement for a manual “over-ride”.
Now we find ourselves in the midst of another evolution. This time it is in robotics, the “InterNet of Things” (IoT), or the “Industrial InterNet of Things” (IIoT) and “Industrie 4.0”. We again have new terms such as “apps”, “IEC 61850”, “storage”, “renewables”, “PV” and “fuzzy logic”. We now have something which is called “The Cloud”.
These technologies will allow us to automate and visualise to an extent that has not been possible previously. The devices and software are already on the market and the applications for the technologies are growing daily. I now do a reasonable proportion of my daily work on my phone and I am not alone in this!
BESST can help you to leverage the operational benefits to be gained from these technologies. Your CAPEX and OPEX should be reduced by implementing the technologies into either your legacy plant or into your next project.
We at BESST show you how to implement the InterNet of Things. We are already busy producing designs and collaborating with partners.