ICS TRIPLEX T8403 Trusted TMR 24 Vdc Digital Input Module 40 Channel

Product overview

The Trusted® TMR 24 Vdc Digital Input module interfaces to 40 field input

devices. Fault tolerance is achieved through a Triple Modular Redundant

(TMR) architecture within the module for each of the 40 input channels.

Each field input is triplicated and the input voltage is measured using a

sigma-delta input circuit. The resulting field voltage measurement is

compared to user configurable threshold voltages to determine the reported

field input state. When a line-monitoring device is installed at the field switch,

the module can detect open and short circuit field cables. Line monitoring

functions are independently configured for each input channel. The

triplicated voltage measurement, coupled with onboard diagnostic testing,

provides comprehensive fault detection and tolerance.

The module provides onboard Sequence of Events (SOE) reporting with a

resolution of 1 ms. A change of state triggers an SOE entry. States are

determined by voltage thresholds that can be configured on a per channel

basis.

Features

• 40 Triple Modular Redundant (TMR) input channels per module.

• Comprehensive, automatic diagnostics and self-test.

• Selectable line monitoring per channel to detect open circuit and short

circuit field wiring faults.

• 2500 V impulse withstand opto/galvanic isolation barrier.

• Onboard Sequence of Events (SOE) reporting with 1 ms resolution.

• Module can be hot-replaced online using dedicated Companion

(adjacent) Slot or SmartSlot (one spare slot for many modules)

configurations.

• Front panel input status LEDs for each channel indicate input status

and field wiring faults.

• Front panel module status LEDs indicate module health and

operational mode (Active, Standby, Educated).

• TϋV Certified IEC 61508 SIL 3.

The Trusted® TMR 24 Vdc Digital Input Module is a member of the Trusted

range of Input/Output (I/O) modules. All Trusted I/O Modules share common

functionality and form. At the most general level, all I/O Modules interface to

the Inter-Module Bus (IMB) which provides power and allows communication

with the Trusted TMR Processor. In addition, all Modules have a field interface

that is used to connect to module specific signals in the field. All Modules are

Triple Modular Redundant (TMR).

Field Termination Unit (FTU)

The Field Termination Unit (FTU) is the section of the I/O Module that

connects all three FIUs to a single field device. The FTU primarily contains

passive components necessary for front-end signal conditioning, field signal

overvoltage protection, and EMI/RFI filtering. When installed in a Trusted

Controller or Expander Chassis, the FTU field connector interconnects to the

I/O cable assembly attached at the rear of the Chassis.

The SmartSlot link is passed from the HIU to the field connections via the

FTU. These signals go directly to the I/O cable assembly and maintain

isolation from the I/O signals on the FTU. The SmartSlot link is the intelligent

connection between Active and Standby Modules for coordination during

Module replacement.

Field Interface Unit (FIU)

The Field Interface Unit (FIU) is the section of the Module that contains the

specific circuits necessary to interface to the particular types of field I/O

signals. Each Module has three FIUs, one per slice. For the TMR 24 Vdc Digital

Input Module, the FIU contains an individual analog to digital (A/D) converter

for each of the 40 field inputs.

The FIU receives isolated power from the HIU for logic. The FIU provides

additional power conditioning for the operational voltages required by the

FIU circuitry. An isolated 6.25 Mbit/s serial link connects each FIU to one of

the HIU slices.

The FIU also measures a range of onboard “housekeeping” signals that assist

in monitoring the performance and operating conditions of the Module.

These signals include power supply voltages, current consumption, onboard

reference voltages and board temperature.

Host Interface Unit (HIU)

The HIU is the point of access to the Inter Module Bus (IMB) for the Module.

It also provides power distribution and local programmable processing

power. The HIU is the only section of the I/O Module to directly connect to the

IMB Backplane. The HIU is common to most Trusted I/O types and has type

dependent and product range common functions. Each HIU contains three

independent slices, commonly referred to as A, B, and C.

All interconnections between the three slices incorporate isolation to prevent

any fault interaction between the slices. Each slice is considered a Fault

Containment Region (FCR), as a fault on one slice has no effect on the

operation of the other slices.

The HIU provides the following services common to the modules in the

family:

• High Speed Fault Tolerant Communications with the TMR Processor

via the IMB interface.

• FCR Interconnect Bus between slices to vote incoming IMB data and

distribute outgoing I/O Module data to the IMB.

• Optically isolated serial data interface to the FIU slices.

• Redundant power sharing of dual 24 Vdc chassis supply voltage and

power regulation for logic power to HIU circuitry.

• Magnetically isolated power to the FIU slices.

• Serial data interface to the FPU for Module status LEDs.

• SmartSlot link between active and standby modules for coordination

during Module replacement.

• Digital Signal Processing to perform local data reduction and self

diagnostics.

• Local memory resources for storing Module operation, configuration,

and field I/O data.

• Onboard housekeeping, which monitors reference voltages, current

consumption and board temperature.