March 13, 2012 - Moore Industries produced a video showing how its STA Safety Trip Alarm serves as a logic solver that goes beyond what customers would expect from a standard alarm trip. The video shows how the STA can monitor potentially hazardous events as well as initiating emergency shutdown procedures or alerting personnel of unsafe process conditions. The video features a demonstration of how the STA serves as a Single Loop Logic Solver in Safety Instrumented Systems (SIS). In the video, the STA monitors a “hot pot” filled with water. When the temperature goes above or below a set point, dual alarm outputs on the STA signal a warning that an unsafe state has been reached.
The video also shows how a third alarm monitors input or instrument faults such as a disconnected wire. The STA performs some of the same functions as expensive safety PLCs but is more affordable and easier to program. The process alarm trips and analog outputs are user configurable via front-panel push buttons. Configurations can be downloaded to multiple STA units with a free software utility program. It has been subjected to extensive testing by TUV and Exida and approved for IEC 61508 and 61511 compliance, including single use in Safety Instrumented Systems up to SIL 2 and firmware suitable for use in a SIL 3 system.
