T8431C Invensys Triconex

The T8431C is the core I/O module in the Trusted TMR series. Designed specifically for safety-critical industrial control systems, this module is particularly well-suited for applications that demand extremely high system reliability, such as Safety Instrumented Systems (SIS), Emergency Shutdown Systems (ESD), and Flame and Gas Detection Systems (F&G).

The module's primary function is to accurately acquire analog signals from the field and transmit them safely and reliably to the TMR controller within the Trusted system. Powered by a 24 Vdc industrial power supply, the module offers flexible configuration options and supports both current signals (such as 4-20 mA temperature, pressure, and flow transmitters) and voltage signals.

• Product Type: Trusted TMR Analog Input Module
• Series: Trusted TMR Series
• Number of Input Channels: 40 channels
• Input Signal Type: 0-22 mA current / 0-6 VDC voltage
• Sampling Update Time: 0.5 ms
• Resolution: 3.9 μA (1/256 mA)
• Measurement Accuracy: ±1% of full scale
• Calibration Accuracy: 0.03%
• Operating Voltage: 20-32 VDC
• Power Consumption: Approx. 15-18 W
• Operating Temperature: -5°C to +60°C (some models support -40°C to +70°C)
• Storage Temperature: -25°C to +70°C
• Relative Humidity: 10% to 95% RH (non-condensing)
• Isolation Voltage: 2500 Vrms
• Protection Rating: IP20
• Mounting: 19-inch rack mounting (4TE slots)
• Safety Certification: SIL 3 (IEC 61508)

1. Ensure that the field cable assembly is installed and properly positioned
2. Use the release key to release the eject latch on the module, ensuring that the latch is fully open
3. Hold the ejector and carefully insert the module into the target slot
4. Press down on the top and bottom of the module's faceplate to push the module fully into place
5. Close the module ejector and ensure it snaps into the locked position

In power plants, the T8431C is used in overspeed protection systems for gas turbines and steam turbines, as well as in safety interlock systems for boilers. The module monitors key parameters such as rotational speed, temperature, pressure, and vibration in real time. If any parameter exceeds the safe range, it immediately triggers a shutdown protection mechanism to prevent equipment damage and personal injury.

What types of input signals does the T8431C support?
The T8431C supports 0-22 mA current inputs and 0-6 VDC voltage inputs, and can be configured for various standard industrial signal ranges, such as 0-10 V, 0-20 mA, and 4-20 mA.

Does the T8431C support hot-swapping?
Yes. The T8431C supports hot-swap functionality. In Companion Slot or SmartSlot configurations, faulty modules can be replaced while the system is running, without the need for downtime.

What is the calibration cycle for the T8431C?
It is recommended to perform a calibration check on the input channels every two years. This check detects long-term drift and any resulting inaccuracies.

T8431 Datasheet (PDF)