Analog Input Module - 40 Channel (T8431) Technical Overview

1. Module Function & Interface

The Analog Input Module - 40 Channel (T8431) is a TMR (Triple Modular Redundancy) 24V dc module 

designed to interface with 40 sourcing field input devices. It acts as a current sink for these devices, 

enabling accurate analog signal acquisition in industrial control systems (see Figure 6-10: Analog Input 

Module for physical reference).

2. Cable Fault Detection & Line Monitoring

The module features built-in line-monitoring capabilities for robust diagnostics:

Open & Shorted Cable Detection: It can identify open and shorted field cables, ensuring early detection of 

physical connection issues.

Independent Channel Configuration: Line monitoring functions are configured independently for each input 

channel, allowing granular control and tailored diagnostics for every analog input.

3. Sequence of Events (SOE) Reporting

For applications requiring precise event timing, the module offers:

1ms Resolution SOE: On-board Sequence of Events reporting with a resolution of 1ms. Any change of 

state in an input channel triggers an SOE entry, enabling accurate tracking of analog signal transitions.

Per-Channel Threshold Configuration: States are determined by voltage thresholds that can be configured 

on a per-channel basis, adapting to the specific sensitivity needs of different analog signals.

4. Status LEDs & Indicator Customization

The module’s front panel includes input status LEDs, with their behavior tied to the voltage level of the 

field I/O signal:

Threshold Bands & LED Modes: Each field input voltage is measured and compared against six threshold 

levels (four configurable, two fixed), creating seven threshold bands (detailed in Section 8). Each band can 

be assigned a specific indicator mode: off, solid green, flashing green, solid red, or flashing red.

Example LED Indications (summarized in Table 6-4: Example of Analog Input Module LED Indications):

Off: Under-range

Red – flashing: Line fault

Green – steady: Low, Normal, High, High-High

Red – flashing: Over-range

Red – steady: Unknown

Customization Flexibility: Users can tailor LED indications to match the operational semantics of their 

analog inputs, ensuring intuitive status visualization for operators and maintenance personnel.

5. Application Suitability

The T8431 module is well-suited for industrial environments that demand:

High-density analog input (40 channels in a single module).

Redundant signal acquisition (TMR architecture) for critical processes.

Detailed fault diagnostics (cable faults, range violations).

Precise event timing (1ms SOE) for analog signal monitoring and control.

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.