Process engineers demanded cost-effective and compact logic solvers with built-in voting capability for plant-critical IEC 61508 Functional Safety applications, and Moore Industries has released the SLA Multiloop and Multifunction Safety Logic Solver and Alarm in response to the demand.
As part of the Moore’s FS Functional Safety Series, the SLA is designed and built to IEC 61508:2010 standards and is exida-certified for use in safety instrumented systems (SIS) for systematic integrity up to SIL 3 and for random integrity up to SIL 2, according to a Moore media release.
This means the SLA is approved for single use in safety applications up to SIL 2 and in a redundant architecture (1oo2, 2oo3, etc.) up to SIL 3. FMEDA certified safety data is available upon request allowing a functional safety practitioner to access the FMEDA data on the SLA to determine the SLA’s applicability in specific safety-related applications.
The SLA performs as a multiloop logic solver with built-in voting and enhanced math capability typically found in costly and complex safety PLCs, according to Moore Industries. This allows the SLA to handle everything from simple alarming to more complex schemes that include 1oo2, 2oo3 or even 5oo8 voting architectures, enabling it to act on potentially hazardous process conditions, warn of unwanted process conditions, provide emergency shutdown or provide on/off control in SIS and traditional alarm trip applications.
“The IEC 61508 certified SLA finally provides safety practitioners with a cost-effective, powerful yet easy to employ multichannel safety logic solver that fills the large functionality gap between high-end Safety PLCs and the limited capabilities of Single Loop Logic Solvers within Safety Instrumented Systems,” said Scott Saunders, president and CEO of Moore Industries.
More features of the new logic server
The four-wire (line/mains powered) SLA accepts up to four discrete and six analog inputs from a wide array of devices and sensors. HART data from connected field devices is passed through the SLA to its analog outputs enabling connected hosts and asset managers bi-directional communication for continuous monitoring and programming.
The unit’s four relay outputs and up to four discrete contact closure outputs can be driven by any of 16 internally configured alarms, where individual or multiple alarms can be assigned to each relay or discrete output. Relay and discrete outputs can also be triggered by any input or internal diagnostic fault. Three optional analog outputs allow transmission of any input or internally calculated equation or variable.
The SLA is easily programmable with any FDT compliant host utilizing the SLA’s DTM with simple drop-down menus and checkboxes. No custom or licensed software is required. This ease-of-use functionality includes a powerful equation editor that the user can employ to create monitoring, alarming and control schemes involving simple to complex equations using timers, running min/max functions, prebuilt analog and discrete logic functions and more.
The SLA features secure programming and communications with security jumpers that can be set to prevent unauthorized reprogramming and ensure read-only communications through the Ethernet and MODBUS ports. It supports MODBUS/TCP and MODBUS RTU industrial protocols and has an embedded read-only web server that allows all inputs, outputs, internal variables and various other parameters to be read with a simple web browser.
