Support For Safety System Requirements; Redundancy Functionality - ABB S800 Product Manual

Section 2 Product Description

Support for Safety System Requirements

The High Integrity I/O is certified for EN 61508-SIL3. The High Integrity I/O has to
be used together with a certified controller to comply with the standards. There are
three modules that belong to the High Integrity I/O family that are certified for these
standards, AI880/AI880A, DI880 and DO880. The modules are supported by the
AC 800M controller PM865 only and have to use the Optical ModuleBus Modem
TB840 when adding optical clusters.
Make sure installation is carried out observing the requirement and guidelines in
the documentation.
FCIs and TB820 cannot handle High Integrity I/O modules.

Redundancy Functionality

Fieldbus Communication Interface (FCI)
When using redundant FCI, one is primary and one is secondary. If the primary FCI
fails it will hand over to the secondary FCI.
If using redundant FCI and redundant electrical ModuleBus, the primary FCI will
control both electrical ModuleBuses. When the primary FCI fails, the secondary
FCI will take control of both electrical ModuleBuses.
Input Modules
When using redundant input modules, all reading is done from the primary input
module. The input module will diagnose itself, and when the primary input module
fails the secondary input module will be set as primary instead.
The secondary input module is checked for error status at a lower cycle rate than the
primary.
Analog Output Modules
When using redundant AO modules, half the output current is generated from each
AO module. The AO module will diagnose itself, and when one fails, it disconnects
and a direct communication between the two redundant AO modules will ensure
that the second AO module quickly doubles its output current.
3BSE015969-600 A
Support for Safety System Requirements
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