IEC 61511 Functional Safety has gained acceptance across global industrial processing, mining, and manufacturing sectors. At the heart of this standard are prescriptive guidelines revolving around Safety Instrumented Systems (SIS) that mitigate risks to protect personnel, facilities, and the environment. Each SIS includes one or more Safety Instrumented Functions (SIFs) that help ensure safe operation.

The logic solver, a crucial component of each SIF, determines when dangerous conditions exist and executes actions that mitigate unwanted or unsafe conditions. Currently, a large gap exists between simplex and complex logic solvers – as it relates to point/loop count, complexity requirements, and cost. Low point count logic solver requirements are often handled with single loop logic solvers while larger safety systems with high point counts are tackled with larger and costly Safety PLCs.

The SLA Multiloop and Multifunction Safety Logic Solver and Alarm from Moore Industries serves as a pivotal bridge between a single-loop logic solver and a Safety Programmable Logic Controller (PLC), enhancing the functionality and flexibility of industrial control systems. Unlike a single-loop logic solver, which handles only one specific control function, and the pricey Safety PLC, which is designed for more complex and higher point counts, the SLA strikes a balance by efficiently managing multiple control loops within a process at a reasonable cost.

Essentially, the SLA logic solver fills the gap, mitigating the drawbacks of a single-loop system and offering a more efficient and affordable substitute for the all-inclusive but sometimes intricate and costly Safety PLC. When a Safety PLC is too complex or resource-intensive for just a few loops, or when a SIF needs multiple inputs for a 2oo3 voting scheme, the SLA is especially effective.

Additionally, the SLA offers an easy scalable solution that can augment the existing capabilities of an in situ Safety PLC. By offering a flexible and tailored control solution that harmonizes the ease of use of a single-loop logic solver with the extensive control capabilities of a Safety PLC, this hybrid logic solver technology effectively bridges the gap.

Keeping Programming and Communications Secure.

The SLA has an Ethernet port and supports MODBUS/TCP and MODBUS RTU industrial protocols. For added security, read-only communication is permitted over these protocols. The SLA does not support write commands from MODBUS/TCP or MODBUS RTU hosts. The built-in web server supporting HTTPS in the SLA provides quick and easy read-only viewing of inputs, alarms, outputs, internal variables, faults, warnings and more via any standard web browser. Prebuilt web pages include simple-to-navigate menus and tables that neatly lay out all the SLA’s parameters.

Moore Industries-International, Inc.