People who have spent time working with computer networks know there’s connected and there’s connected. IT people who work with state-of-the-art networks understand what connected really means: lots of data can go anywhere really fast. Process manufacturers, on the other hand, look at their plants and see all those networks of field instruments and devices all interconnected with current loops, Modbus and other legacy protocols. Maybe there’s some Ethernet in a few places if they’re lucky, but it can’t reach any field devices.
To those IT people, process plants networks are often confusing, but in the right hands can lead to a truly connected enterprise, needed to improve operations. That’s the main point of Josh Hernandez's article, Building a Connected Process Manufacturing Industry, in the December issue of Manufacturing Business Technology.
Networks need to connect components such as programmable logic controllers (PLCs), remote terminal units and other automation system elements. The reach of networks is getting deeper all the time as the number and variety of components grows. This is critical to implementing modern manufacturing concepts where it may be necessary to make regular adjustments to products and processes to keep up with changes in market demand, feedstock changes and other factors.
So where does that leave most process manufacturers?
Process manufacturers like to point out that they’ve had connected plants for a long time. But in many cases, this just means most analog field devices are connected to a distributed control system (DCS). The only way to gather information from them is through the DCS, which depending on its age, may be much easier said than done. Getting information from a process historian may help, but outside of the most modern DCS architectures, platforms designed 15 or 20 years ago did not anticipate the need to have the kind of connectivity necessary to send device-level information to other users within the company. Making it happen often requires extensive custom code writing, if it can be done at all.
So how does the IT person reach into this environment and gather information? Can it be done at all? Josh offers some pointers.
So if a process manufacturer wants to reach down deeper and gather information directly from devices at network Level 1 and Level 0, are there any practical options? The answer usually requires going around existing legacy networks. The most practical approach is using a wireless instrumentation network to supplement the existing wired system. It has to work hand-in-hand with wired and wireless plant Ethernet networks for maximum effectiveness.
The wireless network, in this case, is WirelessHART which can be added to any HART-enabled field device equipped with HART 5 or higher, which is pretty much anything installed in the last 15 years, and often before. The Emerson Wireless 775 THUM Adapter can be added without interfering with the existing wired connection to the DCS. This allows the means to move information to OT and IT networks via a WirelessHART Gateway. It’s somewhat ironic, but this new network will often be able to get more information from those devices than the DCS.
You can find more information like this and meet with other people looking at the same kinds of situations in the Emerson Exchange365 community. It’s a place where you can communicate and exchange information with experts and peers in all sorts of industries around the world. Look for the IIoT Groups and other specialty areas for suggestions and answers.
Posted by Deanna Johnson, Rosemount Measurement & Analytical Global Marcom Manager, Emerson Automation Solutions