T8451 ICS Triplex TMR Digital Output Module

Description:

The TrustedTM TMR 24V dc Digital Output Module interfaces to 40 field output devices. Outputs are arranged in five 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 40 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 TrustedTM 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 six-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 TrustedTM 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 or in a designated SmartSlot with a temporary connection to the same TrustedTM Termination Assembly.

Each output is user configurable to perform 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 TrustedTM 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 TrustedTM Toolset running on an Engineering Workstation. Once configured and loaded into the TrustedTM Controller, replacement modules are on-line educated by the TMR Processor. 

FEATURES

40 TMR output channels per module


Five isolated groups of eight outputs each


Six-element voted output array


Comprehensive diagnostics and self-test


Guaranteed, First fault – Fault Tolerant, Second fault – Fail Safe


Line monitoring on a per channel basis


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 

Parameters:

Model Number: T8451
Type: TMR
Nominal Voltage: 24 VDC
Voltage Range: 20-32 VDC
Voltage Drop: < 4V, typicalNumber of Outputs 40 Channels
No. of Independent Power Groups 5, each of 8 outputs
Field Common Isolation
Sustained Working ±250V dc
 Maximum Withstanding ±2.5kV dc
Output Voltage Field Supply
Measurement Range 0 to 36V dc
Maximum Withstanding -1 to 60V dc
Output Current Rating
Continuous 2A
Output Off Resistance (effective leakage) 33k
Power Consumption (1A per channel) 24W
Output Turn On/Off Delay 0.5ms
Self-Test Internal 2 minutes
Output Short Circuit Protection Automatic
Fusing Not required
Intrinsic Safety External barrier
Circuit Type Fault tolerant, fully triplicated with optional line monitoring