A field trip this week to a pilot distillation facility on the University of Texas campus gave me new perspective on the challenges of delivering wireless in outdoor, industrial settings.
Peter Zornio, chief technology officer with Emerson Automation Solutions, gave me several examples of how wireless could go wrong in these locales. The most obvious challenge is the preponderance of metal in these environments. Wireless signals can’t go through metal, so mesh networks become critical.
Another challenge is the movement of vehicles such as trucks or trains that can get between wireless sensors and gateways. Zornio shared a story about a plant that had an otherwise perfect network that would randomly go down. After some research, the workers realized that a train pulled up twice a day between the facility and the gateway. Mesh networks fixed that as well.
Chemicals are the other big challenge. In a distillation plant (and in other chemical processes) huge vats are filled with liquids that periodically replenish and deplete. Wireless signals aren’t great when it comes to water, so the changing volumes of liquids around the facilities can change the RF environment.
Any good RF engineer can tell you this, but as more and more companies try to build wireless networks in their own warehouses, or even in their stores, it’s worth a reminder that mesh networks are generally good and the RF environment matters tremendously.
Hey Stacey, I read this some time ago and wanted to add some comments. I worked a very large refinery in southeast Texas (recently retired). The site dabbled it wireless networking for the control systems, but there are always concerns about reliability and security when your are dealing with process control . We looked at mesh networking but the cost is very high to do it for the entire site and is hard to financial justify. They are now implementing wireless Hart on a case by case basis. The other issue is the business wireless verses the control system wireless. There is a limited spectrum so if you want plant-wide wireless for both, you need to have both the control systems networking personnel and the business networking folks working together on a design. Not sure what other companies are doing but this was still an unresolved problem the last time I talked with the people at the refinery.