Rockwell Automation T8442 Trusted TMR Speed Monitor - Manual (Page 12)

Trusted
TM
Module T8442
Issue 8 Apr 10 PD-T8442 12
Figure 2 Functional Block Diagram
1.2.1. Host Interface Unit (HIU)
The HIU is a common hardware platform used within all Trusted TM series 8000 I/O modules. It provides
the fault-tolerant communications, control, and processing facilities for the T8442 module. The HIU is
the point access to the Trusted
TM Inter Module Bus (IMB). Each HIU slice is considered a Fault
Containment Region (FCR) in that a fault on one slice has no effect on the operation of the other
slices. All data sent to the module from the Trusted
TM system processor is 2oo3 voted by each HIU
slice. The HIU has house keeping and automatic test functions. The HIU also carries out time
stamping of input and output changes for Sequence of Event (SOE) recording.
The two main elements of each HIU slice are the Digital Signal Processor (DSP) and Host Interface
ASIC (HIA). The DSP provides the data processing capability while the HIA provides module specific
hardware communication and voting logic between the DSP, FIU and IMB. Each HIU slice is clock
asynchronous with respect to the other two slices.
The T8442 module HIA is referred to as the SHIA (Speed Host Interface ASIC).
1.2.2. Speed Field Interface Unit (SFIU)
The Field Interface Unit (FIU) connects the HIU to the Field Termination Unit (FTU).
The T8442 module FIU is referred to as the SFIU.
The SFIU utilises a hybrid redundant architecture with quad-redundancy to achieve fault tolerant output
control and triple-redundancy to achieve fault tolerant speed monitoring. The Speed Field Interface
ASICs (SFIA) provide the interfaces between the HIU and the quad/triple-redundant I/O circuits and
dual-redundant status monitoring circuits. The SFIA circuits are galvanically isolated from the relay
driver and speed input detector circuits. Redundant power supplies are used.
Front Panel Unit
(FPU)
A
SFIA
Q1
SFIA
Q2
SFIA
Q3
SFIA
Q4
Isolation Boundary (Power & Sigs)
Cmd Voting and Response Distribution
Host
Interface
Unit
(HIU)
Speed
Field
Interface
Unit
(SFIU)
Speed Field Termination Unit (SFTU)
IMB (Trusted System Interface)
FIELD INTERFACE CABLE
TC-801
Pulse
Detectors
(Triple)
Relay Drivers
(Quad)
Monitoring -
contacts,
imon, vmon
(Dual)
24V Fused Power
(Quad)
SHIA
DSP
B C
Smart Slot
Link
15V Isense Power
(Dual)
T8891
SOFTA
Output
Relays
(Quad)
Output
Relays
(Quad)
T8846
SIFTA
Pulse
Inputs
T8891
SOFTA
Output
Relays
(Quad)
Output
Relays
(Quad)
T8891
SOFTA
Output
Relays
(Quad)
Output
Relays
(Quad)
SHIA
DSP
SHIA
DSP
TM