Taking the step toward integrated safety using GuardLogix® controllers does not have to be costly or complex. At its very definition GuardLogix® is a simplified Logix processor that provides both safety and standard control in one controller to achieve SIL 3, PLe in a single project. Understanding the reasoning behind your hesitations can help you decide if GuardLogix is the right option for your application.
If your design requires several safety relays and potentially any type or logic, such as time delays or multiple zones, using a GuardLogix could be a cost-effective solution. Surprisingly, the incremental cost adder to go from a standard to SIL2 Safety Compact GuardLogix is only a few hundred dollars.
Beyond the base hardware, the next consideration is wiring. Wiring to IO modules instead of multiple interconnected relays saves time and money. Taking the next step of using drives or integrated motion with CIP Safety via the network can eliminate hardwiring. Using a safety controller directly also reduces or eliminates the need to wire auxiliary contacts from safety devices for annunciation and diagnostic purposes, which could add up to be quite a bit of savings.
If you think programming a safety controller is difficult or complex, using GuardLogix is no more difficult than the Logix programming you are already used to. The structure of the application within Studio 5000 takes the guess work out of how to set up the safety portion. The safety task is created and totally isolated from the standard portion of the controller. It uses the same relay ladder logic for program creation as the standard controller. Additionally, there are certified safe function blocks that can be used to take the guess work out of program creation. Then, to ease adding status information between the safety and standard tasks there is a fill in the blank tag mapping tool.
Once you are finished adding a password to secure the safety function, a safety signature is generated to document against any changes. The signature is unique, and time stamped to ensure that no one has made any changes to the system safety function. By comparing when connected to controller it’s a quick check to ensure nothing has been changed.
To further assist, if you are still unsure or don’t know where to get started Rockwell has a library of documented safety functions. This is the list of documentation that is available with each integrated safety function. They are designed to take the guesswork out of safety integration saving you time and money.
The goal of these integrated safety functions is to minimize risk and improve development speed. Examples of the information that is provided in the safety functions documents include:
Simply match up to what your particular needs are and use what has already been created, tested and documented to get started.
You can find them here:
Rockwell Automation Safety Functions
Search for a document by common applications, or by products and safety rating standards.
Accompanying all of the above ‘ease factors’, the highest level of safety integration is available with Rockwell PowerFlex 755 Drives and Kinetix 5700 Servo Drives. With the addition of a 20-750-S4 Safety option module and possibly additional feedback hardware to the 755, you can also take advantage of the following network safety functions:
If your system requires the use of both VFDs and servo drives, the programming is done in the same way for a simplified user experience. This highly integrated solution of Compact GuardLogix 5380ES or GuardLogix 5580ES controller and PowerFlex 755 with S4 option card can for safety ratings up to and including SIL CL3 and PLe Cat 4. The option module also includes for safety inputs and 2 safety outputs to make wiring of safety devices easier.
If you’re still not sure that moving to an Integrated Safety solution will save you time and money take a look at the following excerpt from an Aberdeen Group white paper titled: “Integrated Safety Systems – Ensuring Safety and Operational Performance.”
Aberdeen surveyed executives about their safety program and technologies and then used the following four key performance criteria to distinguish Best-In-Class companies:
Survey results show that the firms enjoying Best-In-Class performance shared several common characteristics including:
If you would like to read the entire white paper it can be found here: Aberdeen Integrated Safety Systems
Don’t be one of the Laggard organizations, cost and complexity might not be what you think. Contact your Rumsey representative to find out how implementing an Integrated Safety System can turn your company into Best-In-Class performance.