Function Features:

• 8 input channels per module
• Input type: RTD (Pt100, JPt100, Cu50) or Thermocouple (Type K, J, T, E, R, S, B, N)
• 3-wire RTD measurement with lead wire resistance compensation
• Cold junction compensation (CJC) for thermocouple inputs
• 24-bit A/D converter for high-resolution measurement
• Channel-to-channel isolation (500 V AC)
• Built-in linearization tables for all standard TC types

Technical Specifications:

Material Composition:

• Housing: ABS engineering plastic (flame-retardant)
• Terminal blocks: Phosphor bronze with gold plating
• PCB: FR-4 with conformal coating
• Connector: 64-pin DIN 41612 compatible edge connector

Structure Characteristics:

• DIN rail or backplane mounting (FAST/TOOLS chassis)
• Screw-terminal blocks for each input channel (8 pairs)
• DIP switches for input type selection (RTD vs TC, TC type)
• LED indicators per channel for fault detection
• Channel group configuration via software (engineering station)

Working Principle:
Each input channel contains a precision constant current source that excites the RTD or measures the TC voltage. For RTD inputs, a 3-wire measurement method is used: two wires carry the excitation current, and the third wire senses the voltage drop across the RTD, compensating for lead wire resistance. For TC inputs, the module measures the millivolt signal and adds cold junction compensation using an internal temperature sensor. The analog signal is digitized by a 24-bit delta-sigma A/D converter and transmitted to the FAST/TOOLS controller via the system bus. Channel-to-channel isolation is achieved using optical couplers or isolation amplifiers on each channel.

Advantages & Highlights:

• 8 channels per module reduces system cost and wiring
• 3-wire RTD compensation eliminates lead resistance errors up to 10 Ω
• Universal TC support (all 8 standard types) eliminates need for multiple modules
• 24-bit resolution provides superior measurement granularity
• 500 V channel isolation ensures noise immunity in electrically harsh environments

Applicable Industries:

• Power Generation (boiler temperature, turbine exhaust)
• Chemical Processing (reactor temperature, distillation column)
• Oil Refining (furnace temperature, heat exchanger monitoring)
• Pharmaceutical (lyophilizer temperature, cleanroom HVAC)
• Food Processing (pasteurization temperature, cold storage)
• Metallurgy (furnace temperature, annealing oven)

Installation Requirements:

• Install in FAST/TOOLS DCS chassis with adequate airflow
• Route RTD/TC cables away from power cables (minimum 100 mm separation)
• Use shielded twisted-pair cable for TC inputs (Type K: 24 AWG minimum)
• Use 3-wire shielded cable for RTD inputs (max lead resistance 10 Ω per wire)
• Ground shield at controller end only (single-point grounding)
• Maximum cable length: 100 m (RTD), 50 m (TC) without signal degradation

Usage Precautions:

• Do not mix RTD and TC inputs on the same channel group without proper configuration
• Verify TC type matches DIP switch setting (mismatch causes large measurement errors)
• Do not apply voltage > 30 V DC to any input terminal
• Re-calibrate annually for critical process measurements
• Do not disconnect TC while the module is energized (thermocouple break detection will trigger alarm)
• Ensure cold junction sensor is not exposed to heat sources (affects CJC accuracy)