Description
The ICS Triplex T8311 is a specialized communication interface module designed for the Trusted™ Triple Modular Redundant (TMR) safety system. Its primary role is to facilitate the expansion of the system by connecting a Controller Chassis to an Expander Chassis, allowing for high-speed data transparently across multiple racks.
Product Introduction
The T8311 Trusted TMR Expander Interface is a critical component for large-scale safety instrumented systems (SIS). In complex industrial environments—such as offshore oil platforms or large chemical refineries—the number of I/O points often exceeds the capacity of a single chassis. The T8311 allows the central processor to communicate with remote I/O modules located in secondary chassis as if they were residing on the local backplane.
The module operates by extending the Inter-Module Bus (IMB). It utilizes a fault-tolerant, high-speed fiber optic or specialized copper link to maintain the integrity of the TMR architecture across distances. Because it is part of the Trusted family, the T8311 incorporates internal hardware voting and comprehensive self-diagnostics to meet SIL 3 safety requirements.
ICS TRIPLEX T8311
Product Parameters (Datasheet)
The following specifications detail the technical and environmental performance of the T8311:
| Parameter | Specification |
| Model Number | T8311 |
| Product Type | Expander Interface Module |
| Architecture | Triple Modular Redundant (TMR) |
| Safety Rating | SIL 3 (IEC 61508) |
| Interface Speed | 250 Mbps (Bidirectional) |
| Connection Type | Trusted Expander Bus (Specific Cable Sets) |
| Max Expansion Distance | Up to 10 meters (Copper) / 2km (Fiber via media converters) |
| Power Consumption | Approx. 25 Watts |
| Operating Voltage | 24V DC (Internal Bus Power) |
| Status Indicators | Front Panel LEDs (Module Healthy, Active, Fault) |
| Operating Temperature | -5°C to +60°C (23°F to 140°F) |
| Storage Temperature | -25°C to +70°C (-13°F to 158°F) |
Country of Origin
- Origin: United Kingdom (UK)
The ICS Triplex Trusted product line is engineered and manufactured by Rockwell Automation in the United Kingdom. Each T8311 module undergoes rigorous thermal cycling and functional testing to ensure compliance with global safety standards.
Technical Description & Key Features
The T8311 is more than a simple bridge; it is an active participant in the system’s safety integrity:
- Transparent Bus Extension: The T8311 ensures that the 2-out-of-3 (2oo3) voting logic of the Trusted system is maintained across the expander bus. Data from remote I/O is processed with the same determinism as local I/O.
- Fault Isolation: The expander interface is designed to prevent a failure in an expander chassis from affecting the operation of the main controller chassis. It acts as a buffer, ensuring that electrical noise or cable faults do not propagate through the entire system.
- Hot-Standby Capability: In highly critical configurations, T8311 modules can be used in redundant pairs. If one expander link fails, the system automatically switches to the secondary link without any interruption to the process.
- Automatic Addressing: The module assists the system in automatically identifying the slot positions and chassis IDs of remote modules, simplifying the configuration in the Trusted Toolset software.
Product Usage Instructions
1. Installation
- The T8311 must be installed in the dedicated expander slots of the T8100 Trusted Controller Chassis and the T8300 Expander Chassis.
- Align the module with the guide rails and push firmly until the ejector levers click into place.
- Secure the captive screws on the front panel to provide mechanical stability and electrical grounding.
2. Cabling
- Use only approved Trusted Expander Interface Cables.
- Ensure the cables are securely locked into the front-panel connectors.
- In a redundant configuration, ensure that Cable A and Cable B are routed through different conduits to prevent common-cause failure (e.g., physical damage).
3. Commissioning
- Upon power-up, verify that the Healthy LED is solid green.
- Use the system diagnostic software to verify that the central processor recognizes the modules in the expander chassis.
- Check the “Error Count” registers for the expander bus; a high count typically indicates poor cable connections or electromagnetic interference.
Recommended Related ICS Triplex Models
- ICS Triplex T8110B: Trusted Communications Interface (TCI) for high-level networking.
- ICS Triplex T8161B: Trusted TMR Processor, which serves as the controller for the T8311.
- ICS Triplex T8300: The Trusted Expander Chassis that houses the remote I/O and T8311 modules.
- ICS Triplex T8403: 24V DC Digital Input Module commonly used in expander racks.
- ICS Triplex T8431: 24V DC Digital Output Module (TMR) for safety-critical actuations.
