GuardLink Technology – A Smart, Simple, and Safe Control System
January 26, 2022
By Jeremy Sherrell
A safety control system is one of the most critical components of a machine as it guards the crossroads of productivity and operator safety. Safety input devices commonly connect in series for these control systems. While this practice is scalable, it often becomes more challenging to manage when adding new devices to the system. Wiring can be cumbersome, and there is an increase in potential fault points as its complexity grows. Also, it does not provide users with the diagnostic information needed to achieve their equipment’s full potential. Without diagnostics, troubleshooting becomes more complex, downtime becomes prolonged, and users do not have a way to maintain their machines predictively.
Currently, the industry is going through another revolution, and its core is the enablement of Smart Manufacturing. Simply put, Smart Manufacturing means providing valuable information on important issues across the entire business enterprise. With safety being such a vital aspect of every business, it is the perfect place to begin the process of becoming a Smart Manufacturer. By harnessing operational data of a safety system, we can substantially improve safety compliance and performance, increase a machine’s productivity, and minimize its downtime. This practice is called Smart Safety.
Rockwell Automation has a Smart Safety solution that provides users with the simplicity of a series connected safety system, real-time contextual diagnostics, and seamless integration into a Rockwell Automation EtherNet/IP architecture. The Smart Safety solution uses GuardLink, a safety-based communications protocol that links safety to The Connected Enterprise®.
The first component of a GuardLink safety system is the Allen-Bradley® Guardmaster® DG Dual GuardLink™ Safety Relay. This multi-functional safety relay provides up to 20 configurable safety functions with an optional delay in its relay outputs. It supports the implementation of two safety circuits and both Output Safety Switching Device (OSSD) and Electromechanical Safety Switch (EMSS) devices. The relay integrates easily to Studio 5000® Logix Designer software by an Add-on Profile (AOP) and can optically link with the 440R-ENETR Ethernet/IP™ Gateway for connectivity to EtherNet/IP networks. With integration into your Logix Controller, you gain usable and actionable information. For example, a specific tripped device can identify and display on a PanelView HMI so that an operator can take corrective actions. Or historical information can be used for predictive maintenance, so as safety devices reach the end of their life, operators can replace them before failure.
The next component of the GuardLink safety system is the GuardLink Enabled Connection Taps. These taps act as the adapter for safety input devices to connect to GuardLink. Solid-state or electromechanical safety switches can integrate with a separate tap. This system includes guard locking switches, non-contact switches, limit switches, key interlocks, light curtains, and e-stops. The taps also have two bright indicators so that operators can quickly assess and identify the status of the safety system at the device level
Using the Guardmaster DG safety relay in concert with the GuardLink Enabled Connection Taps allows up to 32 safety device connections in a daisy-chained topology through standard cabling with M12 connectors. This relay provides a reduction in wiring, simplifies installation, and reduces potential fault points as compared to a classic series connection of safety devices. Additionally, the relay includes device location, diagnostics, and remote reset and lock commands over the same cable.