Rockwell Automation expands the lineups of both process automation and safety controls with the release of the new Logix SIS platform, which uses the Flex 5000 I/O modules.
Rockwell Automation and Allen Bradley currently have an extensive catalog of safety PLCs, automation controllers, and safety-rated field devices. Recently, Rockwell Automation has expanded its safety component catalog to include the Logix SIS platform, which offers robust communication protocols and system compatibility.
Safety Systems In Automation
A solid safety system will protect operators from harm and help keep production running smoothly. Whenever automated equipment moves components, and there is a potential hazard, a safety system needs to be integrated. A solid safety system comprises a safety controller, rated contacts and sensors, and door locks and switches. These components are combined and programmed in the safety controller. The lowest-rated device determines the level of safety. If your controller is rated for SIL 3 but uses SIL 2 door switches, your system is rated for SIL 2.
The entire Logix SIS platform with Flex 5000 I/O safety modules, Image used courtesy of Rockwell Automation
Logix SIS
Built on the same platform as the 5580 process controller, the Logix SIS is an SIL 2 or SIL 3 safety-rated controller. Like the GuardLogix 5580 processors, the Logix SIS is for process safety. The controller uses the popular Flex 5000 I/O modules for safe digital inputs and outputs. Studio 5000 is used to program the entire solution.
With the Logix SIS platform integrated with the Flex 5000 I/O platform, it also works with Rockwell’s PlantPAx, Distributed Control System, and the Basic Process Control System. Both the Logix SIS and 5580 controllers can exist on the rack and can interface with the same Flex 5000 I/O racks.
Just like the GuardLogix, internal redundancy and failover mechanisms are built into the controller to ensure the logic is always running your safety process.
Test bench setup of the Flex 5000 I/O modules with safety and standard I/O. Image used courtesy of Rockwell Automation
Flex 5000 I/O Modules
Designed for panel distributed I/O in process automation. The Flex 5000 I/O modules are integrated into Rockwell Automation’s process automation controllers and software. The modules support safety inputs and outputs, as well as standard digital I/O and analog with some communication modules. The Flex 5000 communication supports 1 Gbps of either copper or fiber EtherNet/IP protocol and DLR, star, linear, or PRP network topologies. The Flex 5000 I/O system needs to be mounted in an approved control cabinet as it is only IP20 rated.
Operators controlling an automated process. Image used courtesy of Rockwell Automation
Process Safety
In machine building, we think of hazards as components moving around within a fenced-off area, such as robots and servo gantries; With process automation, the hazards could be static, like a large vessel containing boiling liquids or high-pressure gas lines running throughout the plant.
These safety systems work differently than machine automation safety systems. Instead of monitoring fence door switches in your safety program, you might monitor a valve position or a tank door switch. These devices might also be significantly far away from the PLC, which is why the Logix SIS only supports Flex 5000 I/O modules, which has connections suited for longer distances. The purpose of either safety system is to prevent potential hazards from becoming injuries resulting in loss of production.
