Communication chart is a diagram of specified outgoing connection algorithms required for industrial communication programming at production sites. In most European countries, including Germany, the chart is made at the design and survey stage in close cooperation with the customer. Besides, a communication chart is compulsory for Factory Acceptance Test (FAT) where everything is thoroughly inspected. Finally, the On Site Acceptance Test – SAT which is performed after delivery, installation and connection of the equipment on the customer’s site cannot be performed without a communication chart.
Generally speaking, the chart is absolutely indispensable. This is what it looks like:
Now let’s get back to our reality. In Russia, communication charts do not have to be made at the design and survey stage. Design institutes in the Russian Federation do not usually offer the service while customers do not insist on its inclusion just because they do not realize the benefits they can obtain. The benefits, however, are significant.
The communication chart is helpful to designers as it allows getting information on the required equipment fast and facilitates work in general. When looking at the chart, designers can clearly see what devices are required, their quantity, etc. The communication chart can also be used to perform tests and to program the system so that site engineers will only have to install equipment which accelerates its commissioning.
In our country, a communication chart is usually made during installation, at the site, based on the equipment and not the other way round, when equipment is chosen based on the chart. It is inefficient, labor-intensive and time-consuming. It sometimes happens that customers make communication charts themselves at the stage of commissioning work. In this case, the charts may be too extensive, containing lots of unnecessary communications. Engineers eliminate those communications but the work also takes extra time. Besides, you cannot just eliminate a communication: it has to be agreed with the customer first. And the customer does not have a person responsible for this part of the project so that you have to deal with different people every time and explain everything from the beginning again and again.
For example, at Nizhnevartovsk State Regional Power Plant we had to work with a communication chart prepared by the customer. It was quite an extensive diagram covering almost a thousand of algorithms including radio communication. OK, it took us two months to finish programming and then it turned out that there was no loud speaking equipment according to the chart. And additional purchases were already impossible so the chart had to be reduced to adjust all works and fit the new circumstances. If the chart had been made at the stage of design and survey work, those problems would not have arisen.
The Nizhnevartovsk SRPP case clearly demonstrates another crucial advantage of proper preparation of the communication chart: a proper diagram entirely excludes purchasing of unnecessary equipment which has a highly positive impact on the final project cost, operating expenditures of the enterprise and, consequently, on the customer satisfaction.
The conclusion that can be made from the above is quite simple: a communication chart is not just helpful, it is indispensable. And it is better if the chart is made at the designing stage and then always kept at hand. We had a situation when a failure at a large Russian enterprise caused breakdown of all communication algorithms and there was no chart. It was unclear what and how was to be restored and employees had to be asked questions like, “What was on this key? And this one?” If we had had a communication map, it would have taken two or three times less time to eliminate the failure.
Communication chart is required because we do know what may go wrong. And appropriate measures should be taken, at the design and survey stage!