User guide

SDS-8472
Trusted
TM
Industrial Control System
Trusted
TM
TMR 120V ac Digital Output Module-T8472
Issue 4 Feb 2009
FRONT PANEL
DESCRIPTION
The Trusted
TM
TMR 120V ac Digital
Output module interfaces to 16 field
output devices. Outputs are arranged
in two groups of eight outputs. All
outputs in a group share a common
power source and return. Fault
tolerance is achieved through Triple
Modular Redundancy (TMR) within
the same module for each of the 16
output channels.
The module provides on-board
Sequence of Events (SOE) reporting
with a resolution of 1ms. The “event”
is the actual sensing of the field
device loop current.
Each triplicated section (slice) of the
module receives output data from the
Trusted
TM
TMR Processor and sends
its data to an internal safety layer
hardware voter. Each slice uses the
voted data to control the outputs.
Every output channel consists of a
four-element voted array. The output
switch array provides fault tolerant,
uninterrupted control under an output
switch failure condition. Output
switching and fault diagnostics
comply with the demanding
requirements of IEC-61508 SIL-3 for
First Fault - Fault Tolerant, and
Second Fault - Fail Safe outputs.
When a module fault is detected, the
Trusted
TM
TMR Processor will flag the
unhealthy condition, indicating the
need to replace the module. Control
continues until a replacement
(healthy) module is available.
Replacement modules can be located
in a standby slot next to the module.
Each output is capable of performing
line monitoring of the connected field
devices to detect field wiring and load
failures. Automatic over-current
protection is inherent in every output
circuit which eliminates the need for
fuses.
Modules may be placed in any I/O
module slot in a Trusted
TM
Processor
Chassis or Expander chassis. Once
the I/O module configuration is set,
mechanical keying is available on all
I/O modules to prevent inserting a
module into an incorrect slot.
Configuration of the module is carried
out using the Trusted
TM
Toolset
running on an Engineering
Workstation. Once configured and
loaded into the Trusted
TM
Controller,
replacement modules are on-line
educated by the TMR Processor.
FEATURES
 16 TMR output channels per
module
 Two isolated groups of eight
outputs each
 Four-element voted output
array
 Comprehensive diagnostics
and self-test
 Guaranteed, First fault – Fault
Tolerant, Second fault – Fail
Safe
 Short circuit monitoring per
channel when energised
 Open circuit monitoring when
energised or de-energised
 Automatic over-current
protection – no fuses required
 2500V dc Opto-Isolation
 Hot replaceable
 Front panel status LEDs for
each channel
 Module fault and status
indicators
 IEC 61508, SIL 3 safety
applications
 On-board 1 ms resolution
Sequence of Events reporting
T8472 Trusted TMR 120 Vac Digital Output