The AI845 Analog Input Module for single or redundant applications. The module has 8 channels. Each channel can be either a voltage or current input when MTU TU844 or TU845 is used, when other MTUs are used all channels become voltage or current inputs.

The voltage and current input is able to withstand an overvoltage or undervoltage of at least 11 V d.c. The input resistance for voltage input is greater than 10 M ohm and the input resistance for current input is 250 ohm.

The module distributes the external HART compatible transmitter supply to each channel. This adds a simple connection to distribute the supply to 2-wire or 3-wire transmitters. The transmitter power is supervised and current limited.

Detailed data

Resolution 12 bits

Input impedance 10 MΩ (voltage input)

250 Ω (current input)

Isolation Grouped to ground

Under/over range 0 / +15% (0..20 mA, 0..5 V), -12.5% ​​/ +15% (4..20 mA, 1..5 V)

Error Max. 0.1%

Temperature drift Max. 50 ppm/°C

Input filter (rise time 0-90%) 290 ms

Update period 10 ms

Current limitation Built-in current limiting transmitter power

Max. field cable length 600 m (656 code)

Max. input voltage (non-destructive) 11 V d.c.

NMRR, 50Hz, 60Hz > 40 dB

Rated insulation voltage 50 V

Dielectric test voltage 500 V a.c.

Power consumption 3.5 W

Current consumption +5 V Modulebus 100 mA

Current consumption +24 V Modulebus 50 mA

Current consumption +24 V External 265 mA maximum (22 mA + transmitter current * 1.32)

Frequently asked questions about the product are as follows:

-What is the ABB AI845?

The ABB AI845 is an analog input module that converts analog signals into digital data that a control system can process. It is typically used to interface with sensors and devices that produce analog signals, such as temperature sensors (RTDs, thermocouples), pressure transmitters, and other process-related instrumentation.

-What types of input signals can the AI845 module handle?

Current (4-20 mA, 0-20 mA) signals

Voltage (0-10 V, ±10 V, 0-5 V, etc.) signals

Resistance (RTDs, thermistors), with support for specific types such as 2, 3, or 4-wire RTDs

Thermocouples (with appropriate cold junction compensation and linearization)

-What are the power requirements for the AI845?

The AI845 requires a 24V DC power supply to operate.