I sat through a demo the other day of a software application that extracts all the information from your control system and puts it into an offline readable format that the user can query to create custom reports. While it is a wonderfully done package, it would be absolutely useless in many of the plants I’ve visited recently. Most of those plants are in the process of migrating their existing obsolete systems to a platform with current technology.
Everyone knows recipes and specifications. They know that they have them and they use them and so on. And, they know that they have a group or department, probably part of R&D, that’s ultimately responsible for all the recipes and specifications.
Over the last few years, MES (manufacturing execution system) packages have appeared that provide the database framework and programming interfaces to collect, process and provide standardized information links between the production floor below and the ERP (enterprise resource planning) business system above. Even so called “configurable” packages usually require extensive custom coding since the built-in functional capabilities are usually insufficient to handle all but the simplest manufacturing processes and integration to current installed information systems. The reality is that MES installation projects are just as much about custom software development as they are about installation and configuration.
As process control engineers, we are constantly faced with having to choose a type of control system that is a best fit for the application. If you’re an end user, you probably will not need to make this kind of selection as often as we do, so you might not keep up-to-date with the latest technologies. There are many types and manufacturers out there to choose from, and careful consideration must be taken when deciding what type of system to implement into an automatic control application, especially since these systems will often remain in place for many years. A bad decision could haunt you for a long time.
In the last post, I talked about manufacturing traceability and supply chain traceability and hopefully made the case that they’re some big differences between the two. And, even if I didn’t convince you, I hope I at least convinced you to think about it some more and think about what manufacturing traceability really means. So, it’s time to get into it a little more.
No one else in the industry is offering anything like PlantFloor24—the world’s first full-service, platform-independent, 24/7 hardware, software and process support solution. It keeps manufacturing operations online and continuously improving for the long term.
Gary Mintchell, Automation World editor in chief, said it best:
“Technology suppliers have robust service solutions for their own products, but sometimes the finger-pointing about whose system is to blame can override a final solution. Independent integrators such as Maverick are now building expertise to fill that void.”
As we roll out PlantFloor24, you’ll learn more on how this round-the-clock service allows manufacturers to reduce operational costs, augment staff with multidisciplinary skills and improve asset management.
In the meantime, hear from the top automation publications on PlantFloor24 and why it revolutionizes how manufacturers monitor, maintain and optimize their plant.
- Automation World: MAVERICK Technologies Opens PlantFloor24
- Gary Mintchell's Blog: Support Services In Manufacturing A Trend
- ISA’s InTech Blog: Maverick Technologies launches PlantFloor24
- Walt Boyes of Control Global's blog: Maverick Open House: DCSNext and PlantFloor24 #pauto
Have you ever gone online with a PLC and realized it contained no structure, the I/O was all over the place, and there were no comments in the logic? Fortunately, all projects are not retrofits or adding code to an existing PLC program. Sometimes you get to start from scratch. There are some good practices to follow when launching a new project that will help simplify a complicated program and make it easier to follow should someone else need to edit the code in the future.
I often say, “Levels are devils to control.” Why? They’re integrating variables; that is, if the level in a vessel is constant, and the valve is opened or closed and then brought back to its original opening, the level will be at a different place in the vessel. Levels are non-self-regulating – they represent an imbalance between the flow of material into and out of a vessel. The tuning challenge is to find the best combination of gain (or proportional band) and integral time (or reset) that attempts to react to material flow imbalances and maintain the level reasonably close to a set point. For a variety of reasons, using derivative is not a good idea for level control. Gain alone or PI control handles PV trajectory changes quite well.