The Universal Analog Input module supports up to 8 user-configurable inputs on a per-point basis for thermocouple, RTD, resistance, V, mV, and mA. It offers point-to-point isolation and backplane isolation. Modules perform analog-to-digital conversion in synchronization with CPU control execution, eliminating data interchange latency. All analog input modules are processed in parallel, eliminating scan time increases as modules are added. The module has a green blinking status LED when it is being scanned and a red status LED when module diagnostics exist. It supports a user-selectable BURURNOUTN value on a per-channel basis. A warning signal is provided for thermocouple inputs to indicate maintenance is needed before a sensor failure, and a sensor failure signal is also provided.

Item Specification

• Inputs per module: 8 (isolated)
• Input types: mV, V, T/C, RTD, ohms, mA

Signal Source

See Analog Input Reference Accuracy for range types:

• Thermocouple with cold junction compensation
• RTD, PT100 3 wire, 40 ohms balanced maximum
• Thermocouples: 100 Ohms/Leg
• 100 (except Low), 500 & 1000 RTD: 100 Ohms/Leg
• 100-YIS: 100 Ohms/Leg
• 100-Low RTD & 10-ohm Cu: 10 Ohms/Leg
• Input Impedance: 10 megohms for T/C and mV inputs; >1 megohm for volts and 250 ohms for mA inputs
• Galvanic Input Isolation: 400 VDC point to point, 1K VDC to logic
• RTDs are isolated in pairs
• Noise Rejection: Series Mode >60dB, Common Mode >130dB at 120VAC
• Burnout: T/C, mV, V configurable to upscale, downscale, defined value, or none
• Over-range limit: +/- 10% for linear ranges (volts), +/-1% for non-linear ranges (T/C, RTD)
• T/C Break Detection: Via current pulse
• Faulty thermocouple detection: If greater than 100 ohms, a warning status is provided as an output for the AI block
• Accuracy: Factory-configured accuracy = ± 0.1% of range (± 0.2% of range for 0V to 10V and -10V to 10V)
• Cold junction accuracy = ± 0.7 °C
• Reference conditions: Temperature = 25 °C ± 3 °C (77 °F ± 5 °F), Humidity = 45% to 55% RH non-condensing, Line voltage = Nominal ± 1%, Source resistance = 0 ohm, Series mode and common mode = 0 V, Frequency = Nominal ± 1%
• Temp. Effect on Accuracy: ± 0.01% of full scale per degree Celsius maximum
• A/D Converter: One per module
• A/D Resolution: 15 Bits
• Reference Junction Sensing: Via 2 RTDs at top/bottom of module
• Update rate: 500ms (Analog to Digital Converter per module)
• Long-term Stability: 0.1% per year
• Calibration: Data is stored in non-volatile memory, Redundant Factory Calibration Individual
• Diagnostics: Monitoring of Factory Calibration, 24 VDC supply, and configuration
• Channel Configuration: Data Stored in non-volatile memory

Analog Input Reference Accuracy