Understanding Your Automation Control Options: PLCs, PACs, PC-based Controllers
Learn to differentiate “marketing-speak” from fact in this assessment of similarities and differences between automation control platforms.
There are two basic automation control platforms available from automation vendors today; PLCs and PC-based controllers. PLCs come in a wide variety of hardware options and are the most established automation control option on the market today. In contrast, PC-based controllers use a software controller installed on an industrial computer. This allows users to integrate high level computer programming or other PC functionality with automation system control.
The term “PAC” is relatively new in the world of industrial automation and is presented by some vendors as an alternative to the PLC. When vendors discuss PACs they usually talk about a specific set of features they claim differentiates them from PLCs. In reality, many vendors offer these features within their current PLC offering, choosing not to isolate certain features and market them as a separate PAC hardware platform... Read more
The Latest Thinking on Using Ethernet for Machine Safety Networks
A networking expert takes a look at how networked machine safety has evolved, examining the implications of Ethernet-based machine safety networks as a replacement for field buses.
In machine safety, many new approaches, regulations and options have emergedoften being replaced themselves in a fit of Darwinism in a matter of a few short yearsmaking it seemingly difficult to keep up with the state of the art and determining what is right for you and how to apply it.
Ethernet is rapidly emerging as the de facto network for the plant floor communications, replacing field buses in the factory while also providing a link to front office systems. Ethernet has enough speed for manufacturing environments, and it's been enhanced with real time capabilities for the most demanding applications.
In this article, we look at the implications of using Ethernet as a network for machine safety... Read more
Case Study: Dairy Food Company Proves Wireless Networking is Ready for Mission-Critical Control
Texas ice cream manufacturer replaces five aging PLC's with one modern PLC on each of its three automated storage and retrieval systems, all outfitted with wireless Ethernet for control. Also: Seven things to know before implementing wireless on the plant floor.
Although wireless networking is no longer new in the realm of industrial automation, many manufacturers are still reluctant to depend on wireless for control applications.
“The primary concerns people have about trusting automation tasks to wireless controls revolve around security, interference of the wireless signals and slow information transfers,” says Rajesh Rajani, Ethernet infrastructure marketing manager for Atlanta, GA-based Siemens Industry. “So companies have tended to use wireless technologies for monitoring, but not for control.”
However, wireless technologies have evolved to address these issues, and progressive manufacturers are beginning to adopt them. One example is Blue Bell Creameries of Brenham, Texas, which recently upgraded its ailing, 20-year-old Automation Storage and Retrieval System (ASRS) with a system based on Siemens wireless Ethernet components... Read more
Video: Simatic Mobile Panel - Shortcuts for quarry operations
Traditional machine safety system upgrades can be costly and time consuming.
A Simatic Mobile Panel from Siemens Industry controls all system components at a Schnorrpfeil quarry in Germany. The automation solution, which communicates with the system via RFID, makes for more efficient production... View now