PLC Communications via Radio Are a Thing of the Past. A More Reliable Solution Wins
Holcim Czech Republic wanted to replace its radio transfer of remote PLC data with a more reliable solution. We recommended Teltonika industrial routers. This solution has also brought other benefits.
Many companies with large industrial sites use radio communications to transfer control system data. This is also the case for several of our customers. All it takes is a change in the weather, a truck parked in the transmission path, or scaffolding erected nearby, and the information from each device stops flowing. Technicians often have to physically drive around the sites to take data readings or, in the case of critical equipment, to check if it is working at all.
The company HOLCIM (Czech Republic) asked us if we could ensure stable and reliable transfer of its tank pump control system data to the company's control room several kilometres away from the pumps. We could, using Teltonika routers.
Holcim Cement Works Czech Republic is a member of the Holcim Group. It specialises in the production of a wide range of different types of packaged and bulk cements, as well as cements with a reduced carbon footprint, marketed as ECO planet. Some of its other products include limestone clay for flue gas desulphurisation or management of environmental pollution.
Water is a very important part of the cement manufacturing process. It involves various pumps, flow meters, tank level sensors and other equipment, the operation of which is controlled by PLCs. Four pumping stations, located 2-4 km from the control room, were communicating very unreliably with the main PLC. This also included failures in the transfer of data to the OPC DA server. The technicians could not rely on the data transfer and had to make frequent trips to each tank to check its status in person. As a result, their standard work was often neglected.
- We installed Teltonika 4G routers at all the PLCs, which communicate with the router installed in the control room via the customer's SIM cards.
- We updated the software in the PLCs and made the necessary program changes.
- We created VPN communication tunnels for secure communication, defining exactly which devices could communicate with each other.
- We adapted the data reading speeds to the actual traffic requirements so as not to overload the network unnecessarily.
- We removed the previously used OPC DA server, which had been used to read data from the PLCs. It was no longer needed because the customer's KEPServerEX data acquisition software could communicate directly with Teltonika.
- All this was done within a few days.
- A major positive change is the reliability and speed of the communication.
- Two-way communication is a matter of course. Staff in the control room can now read data (e.g. the current flow and valve position) as well as write it to the PLCs (e.g. switch on a pump, open a valve etc.).
- A great advantage, which the customer praises, is the ability to modify the programs in the remote PLCs directly from the control room.
- The data visualisation, which the customer had been used to and comfortable with, remained unchanged after all our modifications, exactly as the customer wanted.
Technicians no longer waste time going round stations, and managers praise the reduced costs and overtime associated with dealing with previous communication breakdowns.