T8311, T8311C, P8311
T8311 Expander interface
Description
The Trusted TMR expander interface module resides in the Trusted controller chassis and provides the ‘master’ interface between the inter-module bus (IMB) in the controller chassis and the expander bus. The expander bus allows multiple chassis systems to be implemented using UTP cable connections whilst maintaining the fault tolerant, high bandwidth IMB capabilities.
The module provides fault containment for the expander bus, the module itself and the IMB in the controller chassis, ensuring that the effects of these potential faults are localized and system availability maximized. The module is fault tolerant with Hardware Implemented Fault Tolerant (HIFT), Triple Modular Redundant (TMR) architecture. Comprehensive diagnostics, monitoring and testing provide rapid fault identification. Hot standby and module sparing configurations are supported, allowing automatic and manual repair strategies.
Communication between the expander interface and the TMR processor is via the IMB on the backplane of the controller chassis. The IMB provides fault tolerance and high bandwidth communications between the interface modules and the TMR processor. All transactions are voted, localizing faults to a Fault Containment Region (FCR) within the IMB they occur.
Communication between the interface module and the TMR expander processor in the expander chassis is via the expander bus. The expander bus is triplicated, point-to-point architecture. Each channel of the expander bus comprises separate command and response media. Voting is provided at the expander bus interface to ensure that cable faults are tolerated, and the remainder of the expander processor operates in a fully triplicated mode, even in case of cable faults occurring.
The TMR expander interface module derives its internal voltages from dual redundant +24V dc power supplied via the module connector from the Trusted controller chassis backplane. Each FCR derives the required supplies independently.
Non-critical monitoring and module status display functions (front panel LEDs) are also provided.

Features
Triple Modular Redundant (TMR) fault tolerant (3-2-0) operation.
Hardware Implemented Fault Tolerant (HIFT) architecture.
Dedicated hardware and software test regimes which provide fast fault recognition and response times.
Automatic fault handling without nuisance alarming.
Hot replaceable.
Front panel status LEDs.