The MTL redundant FISCO power supplies provide an intrinsically safe field network for Foundation fieldbus systems in hazardous areas. Variants are available
for integration into proprietary fieldbus control systems. The output of the power supply modules complies with the Fieldbus Intrinsically Safe Concept (FISCO) model,
in accordance with IEC standard 60079-27. The key advantages of FISCO over earlier Entity model installations to FF-816 are higher available field current and reduced
safety documentation, while retaining the ability to conduct maintenance while energized and without gas clearance.
Each IS fieldbus segment is powered by a redundant pair of pluggable FISCO power supply modules. The modules operate in active, hot standby mode, ensuring that the
fieldbus segments are continually powered. In the event of a failure of an active power supply module, the field circuit is automatically transferred to the standby module.
The changeover is managed by Supply Arbitration Modules (SAMs), which monitor the health of the FISCO power supplies while maintaining intrinsic safety requirements during
the transition to the standby module. The SAMs are also duplicated and replaceable, meaning that there are no non-redundant system components.
Switchover is achieved rapidly and in accordance with Foundation fieldbus specifications, and without risk of losing fieldbus devices from the bus. A combination of LED diagnostics
and alarm signaling provides failure notification of FISCO power supplies and SAMs, allowing failed hardware to be identified and full redundancy to be restored by module replacement.
The 9107-22 is designed for universal, non-powered host control systems, and the 9109-22 is for universal, powered host control systems, including Emerson DeltaV and Honeywell Series C I/O.
The 9101-22 is for use with Invensys Foxboro I/A series, and the 9108-22 is designed for the Yokogawa CENTUM CS3000.
