ICS T8161B TMR Expander Interface Module

1. Basic Information

2. Hardware Specifications

1. Power Supply

   ‑ Backplane supply: 20‑32 VDC (nominal 24 VDC), dual redundant backplane power; power consumption approx. 23‑29 W

2. Processor & Memory

   ‑ On‑board independent TMR 3‑channel co‑processor with hardware 2‑out‑of‑3 voting;

   ‑ On‑board Flash and SDRAM cache for IMB bus forwarding and data validation.

3. Communication Interfaces

   ‑ Backplane IMB TMR bus: connects to T8110C / T8111C main processor in main chassis;

   ‑ External expander bus port: UTP Ethernet port for connecting remote chassis T8161B to realize cross‑chassis TMR bus;

   ‑ Front‑panel LED indicators: Health, Active, Fault, Link status.

4. Environmental Conditions

   ‑ Operating temperature: ‑40℃ ~ +70℃;

   ‑ IP20 (inside cabinet); relative humidity 5‑95% non‑condensing; electrically isolated with fault‑containment design, limiting faults locally without spreading to whole system.

3. Key Functions

1. TMR Triple‑Modular Redundancy Expander‑bus Voting: 3‑channel hardware voting. Single‑channel faults are isolated automatically. Hot‑swap online replacement without disturbing safety logic in main chassis.
2. Multi‑chassis Expansion Interconnection: Acts as bridge between main chassis and remote expansion chassis via UTP cable, expands I/O rack quantity and breaks single‑chassis I/O capacity limit.
3. Fault Containment & Isolation: Faults on expander bus or external cables are isolated by the module and will not propagate to main chassis and CPU, protecting core safety logic.
4. Active‑standby Redundancy: Dual T8161B supports active‑standby hot‑standby with automatic fail‑over for higher link availability.
5. Comprehensive Hardware Self‑diagnosis: Real‑time diagnosis for bus links, channels and cable status, timestamped fault logging; front‑panel LEDs display link status intuitively.
6. Transparent IMB Bus Forwarding: Transparent to upper‑level processors. I/O modules in expansion racks behave as local I/O without special program modification.

4. Typical Applications

5. Important Notes

1. Firmware version must strictly match T8110C / T8111C processor and all system modules. Mismatched firmware causes expander‑bus communication failure. Verify firmware build number for spare‑part replacement.
2. T8161B is only for chassis expander bus. It cannot serve as CPU, cannot replace T8151B for DCS/HMI external communication, and is different from T8160 (legacy Regent system gateway).
3. Use standard compliant UTP cables for expander bus; implement proper cabinet grounding for anti‑interference.
4. Compatible only with dedicated Trusted chassis; not applicable for standard PLC racks.