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Basically, users needed to generate custom configurations of code to select, arrange, and man- age data, and they had to take additional steps to handle extended information like scaling, engineer- ing units, and tag descriptions. A lot of parts and ef- fort might be involved: PLCs, gateways, PCs, software packages, network configuration, and custom code.
Even when data connectivity could be patched together, it was often at the expense of security. Traditionally, PLCs have not in- cluded strong—or any—cybersecurity provi- sions, especially for internet-connected systems.
Solved by Today’s Tech
For best results, all data integration elements need to reside natively in the PLC product, provid- ing an off-the-shelf experience for users. End users, especially in the IT field, are also looking for open source-based solutions because they are already familiar with this approach, as opposed to the spe- cialized environments common to OT products.
Some of the most popular serial and Ethernet protocols for OT purposes include ASCII, Modbus RTU, K-Seq, Modbus TCP, and EtherNet/IP. From an IT stand- point, protocols like SNTP DNS, MQTT, SMTP, SSL, and web service are essential. A PLC bundling these ca- pabilities together becomes a bridge from OT to IT, creating many ways to connect new and legacy fac- tory floor equipment to today’s enterprise systems.
Multiple Options
Following are several popular data integration approaches possible with modern PLCs. Users can se- lect one or more options to best meet their needs.
Store Data in the PLC and Forward via FTP Today’s PLCs have enough memory to log data locally over a period of hours, days, or weeks— and then forward it to a network- or cloud-con- nected computer using FTP. This form of storing and forwarding data can be especially effective for bulk transactions which do not need to be near-re- al-time, however it will require the user to care- fully configure both the PLC for aggregating the data and the host system for parsing the data.
Web Server
Sometimes it is only necessary for a PLC to
expose limited data for read-only, near real-time re- mote viewing by users. In this case, some PLCs in- clude built-in web servers, empowering users to develop HTML5 displays of data and information viewable using browsers. No other additional soft- ware or licensing is required. A downside to this basic approach is the need for clients to be con- nected on the same network—or via a firewall and routing—with the proper access privileges.
Fortunately, some of today’s most mod- ern PLCs include all the elements needed to overcome these challenges, eliminating com- plexity from the task of getting data from the shop floor and up to the cloud and enterprise.
PLCs are already an established and reliable plat- form for edge automation tasks. Instead of creat- ing a new category of device only tasked with data communication duties, some vendors realized that next-generation OT-based PLCs could be enhanced with the necessary IT-associated tech to provide a complete data integration solution (Figure 2)
Figure 2: Next-generation PLCs, like the AutomationDirect BRX Series,
are built from the ground up with OT and IT communication protocols, and the necessary security features, for enabling seamless data integration. With the free programming software, users can configure the BRX (with or without classic I/O) to also act as a data gateway
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