- December 04, 2014
- Rockwell Automation
- Rockwell Automation
By Bill Lewins, Rockwell Automation
Designing and implementing a network that addresses all process control concerns can be a difficult for any application, but brownfield projects are especially challenging. Fortunately, there are ways to ease this transition.
By Bill Lewins, Rockwell Automation, on behalf of Industrial IP Advantage
Designing and implementing a network that addresses all process control concerns can be a difficult for any application, but brownfield projects are especially challenging. After all, people don’t tend to respond well when you tell them that their three-year old, multi-million dollar facility needs a new network. Fortunately, there are ways to ease this transition. Here are a few of them. 1. Understand the requirements The phrase “Here’s your cable,” may not sound overtly threatening, but make no mistake: These words can spell doom for a plant network. That’s because they’re frequently uttered by network engineers who install generic networks without working with plant personnel to discover the unique requirements of an operation and tailor a solution to meet these needs. Before any work can be done on the network, the transition team needs to fully understand the system’s requirements. What are the operational elements within the plant? Which are most critical? What type and quantity of information must be shared among all devices on the network? How do they need to communicate? Like a doctor diagnosing a patient, the most effective way to answer these questions is by examining the plant, its processes and its workers in person. That means conducting a physical walk-through of the actual site. Doing so enables the team to understand the layout of the plant, witness the problems that are occurring, understand how the various operational elements interact with each other, and talk to personnel to assess their needs firsthand. Now the team can begin drafting the blueprint for a highly tailored and efficient network. 2. Create a specific implementation plan. Some engineers will say downtime costs their plant $10,000 or $20,000 an hour. Others will say that five minutes could cost them millions. What’s clear is that these two different plants will have to migrate to new networks in very different ways. Some plants schedule annual shutdowns, allowing time for network migration, but others don’t. Some plants have the flexibility to shut down a zone while continuing other plant operations; others have to completely shut down. The operational demands of each plant will help dictate the timing of its network migration. Coordinating all these details, clearly documenting them in a plan and sharing that plan with everyone involved in the changeover will eliminate confusion and minimize unexpected downtime. 3. Use equipment that meets the environmental needs If you’re not careful about the equipment you install in your plant, you can end up spending the money your new network was designed to save. Take, for example, the customer who wanted to save money by standardizing switches in his plant. Despite the vendor’s advice, the customer chose to use high-end, 48-port POE switches, which did not fit the requirements of the plant’s infrastructure. When these switches were placed into control cabinets in the industrial environment, they did not perform well. So in addition to the $14,000 or so the plant spent on switches, it required a new $2,500 cooling system for each, and time and money replacing the filters for that cooling system – well above the $2,000 cost of the industrial switch suggested by the vendor. The customer’s decision to save money by standardizing switches will probably cost the company hundreds of thousands of dollars over the lifecycle of that plant – simply because they chose the wrong equipment. Don’t fall into the same trap. Make sure that all your equipment is appropriate for your infrastructure and environment. 4. Test it When implementing a plan, never assume everything will work properly. Simply too many things can go wrong and too much is at stake to take success for granted. You have to prove it. Take a boiler, for example. Let’s say a plant is designed to run on four boilers, but it has six boilers in total, allowing two for back-up. You don’t want to migrate three of them and suddenly discover something is wrong, leaving you without enough boiler capacity to run the plant. Instead, validate each boiler before you move on to the next one to prevent problems before they occur. This usually requires having at least one of employee on site who fully understands both the application and process control. That way, each step in the transition can be thoroughly evaluated as it’s completed, and any problems identified and quickly remedied. In truth, the verification process is a lot like brushing your teeth. It takes time and you don’t really want to do it, but it’s worth it because it prevents problems down the road. For more information, visit www.industrial-ip.org.Learn More
Did you enjoy this great article?
Check out our free e-newsletters to read more great articles..Subscribe