ICS T8431C 40‑Channel TMR Analogue Input Module

1. Basic Information

2. Hardware Specifications

1. Electrical & Channel Parameters

   ‑Channel count: 40 channels analogue input; every channel with full TMR triple‑path acquisition and hardware 2‑out‑of‑3 voting

   ‑Input signal:0‑22 mA current (4‑20 mA transmitters) / 0‑6 VDC voltage; module acts as current‑sink for 2‑wire field transmitters

   ‑Resolution:3.9 µA; Calibration accuracy 0.03 % FS; Safety accuracy ±1 % FS

   ‑Backplane power:20‑32 VDC from chassis backplane; typical power consumption 15‑18 W, max.20 W

   ‑Sample update:0.5 ms (without filter); four user‑configurable thresholds per channel; per‑channel line‑monitor for open‑circuit, short‑circuit and over‑range fault detection

   ‑SOE function:On‑board hardware SOE, 1 ms time‑stamp resolution. Timestamp generated locally upon threshold crossing without main‑controller CPU loading

   ‑Isolation:2500 V impulse opto‑galvanic barrier between field and system side; per‑channel configurable 50/60 Hz digital filter

   ‑Hardware enhancement:Full‑board C‑Coat conformal coating against humidity, salt‑spray and corrosive industrial gas for offshore / chemical‑plant service‑life improvement.

2. Front‑panel & Interface

   ‑Front‑panel LEDs:Module OK, Fault, Active / Standby status indicators.

   ‑Rear‑side dual 96‑way connectors interfacing to T8831 FTA. Smart‑slot supports hot‑swap module replacement without disconnection of field wiring.

3. Environmental Conditions

   ‑Operating temperature:0℃ ~ +60℃; Storage temperature:‑40℃ ~ +70℃

   ‑Relative humidity:5‑95 % non‑condensing; IP20 for cabinet installation

   ‑Hazardous‑area rating:C‑series Ex ec IIC T4 GC, superior to B‑series T8431 (Ex nA); enhanced resistance for salt‑mist and corrosive‑gas environment; T8431C is preferred for offshore installations.

3. Key Functions

1. Channel‑wise TMR triple‑redundant 3‑2‑0 hardware voting:Each analogue field signal is duplicated into three independent sampling circuits inside module, hardware 2‑out‑of‑3 voting executed. Single‑path fault is isolated automatically without disturbing corresponding channel or other channels, eliminating single‑point‑of‑failure risk.
2. Per‑channel analogue‑loop diagnostics:With T8831 FTA fitted, line‑monitor can be enabled channel‑by‑channel to detect transmitter open‑circuit, short‑circuit and over‑range faults; timestamped fault messages uploaded to system software.
3. Hardware local SOE reporting:Analogue threshold crossing triggers on‑module 1 ms accurate event timestamp for post‑incident safety analysis.
4. Hot‑swap maintenance:Module can be replaced online; field wiring on FTA side remains connected; other I/O channels keep continuous operation.
5. Universal for main / expander chassis:Installable either in T8100 main chassis or T8300 remote expander chassis; I/O points are fully transparent to main processor.
6. C‑Coat conformal protection:PCB coating protects electronic components from high‑humidity, salt‑spray and corrosive process gas for extended lifetime under severe site conditions.
7. Periodic background self‑test:Automatic built‑in self‑test every 2 minutes; continuous monitoring for backplane bus, triple‑channel circuitry and FTA link for fast fault alarming and localization.

4. Typical Applications

5. Important Notes

1. Must pair with T8831 FTA, field cables cannot connect directly to module. T8831 is DIN‑rail mounted with loop‑protection; FTA is fully shared between T8431 and T8431C.
2. When fitted inside T8300 expander chassis, T8310 expander‑processor must be present in same chassis.
3. Firmware build‑version must strictly match module hardware variant. T8431 firmware cannot run on T8431C and vice‑versa; verify build‑number before spare‑part replacement. Mechanical dimension and pin‑out are 100 % physically compatible, but firmware shall not be mixed.
4. Line‑monitor function must be software‑enabled per‑channel for transmitter wire‑break / short‑circuit detection; without enable only analogue value is read without loop‑fault diagnosis.
5. Module is current‑sink input, suitable for 2‑wire 4‑20 mA transmitters; cannot supply source‑current output; RTD thermal resistance signals require separate T8441 / T8441C RTD module.
6. C‑Coat conformal coating protects printed‑circuit board only. Module must be installed inside suitable cabinet for hazardous‑area compliance.