Expander Interface (T8311) Technical Overview

1. Module Role & System Integration

The Expander Interface (T8311) resides in the controller chassis and acts as a vital bridge, providing an 

interface between the controller chassis and up to seven expander chassis. It enables:

Fault tolerance through HIFT (High Integrity Fault Tolerant) TMR architecture.

Rapid fault identification via comprehensive diagnostics, monitoring, and testing.

Support for standby module configurations, allowing both automatic and manual repair strategies to 

minimize downtime.

2. Physical Installation & Chassis Placement

Slot Requirements: The module can reside in any single-width slot within the controller chassis.

Paired Installation: Modules are installed in pairs, with the left-hand module occupying an odd-numbered 

slot. When both modules in a pair are healthy, the TMR processor designates the left-most module as active 

by default; this ensures a clear operational hierarchy.

3. Power Supply & Redundancy

The expander interface module derives its internal voltages from dual redundant +24V dc power, supplied 

via the module connector from the controller chassis backplane. This redundancy guarantees uninterrupted 

operation even if one power path fails.

4. Status LEDs & Operational Visibility

The module’s status LEDs provide detailed insights into its health and operational mode, as defined in 

Table 5-2: Expander Interface Module LED Indications (and visualized in Figure 5-6: Expander Interface 

Module):

Healthy:

Three LEDs (one per slice) indicate the overall health of each processor slice.

Steady green = Healthy slice.

Flashing red = Fault in the corresponding slice.

Active: Illuminates steady green when the module is in Active mode.

Standby: Illuminates steady green when the module is in Standby mode.

5. Fault Tolerance & Maintenance Capabilities

HIFT TMR Architecture: The module’s design ensures that individual component faults do not compromise 

system integrity, maintaining reliable communication between the controller and expander chassis.

Diagnostics & Repair Workflows: Comprehensive monitoring allows for rapid fault detection, while 

support for standby configurations enables automated failover or manual intervention, ensuring system 

availability during maintenance.

How we deliver

Supply Ability:In stock,within 3 days send the products.

Price:The more you order,the lower price you will get.

Our products is ship with original factory new package.

We will cover our our professional foam protective packaging to keep worldwide shipping no damaged.

We have many couirer partner,like DHL,TNT,FeDex and UPS

The factory will strictly test all the goods before shipment,and the warehouse staff will also check the 

integrity of the product packaging when it is shipped.