HIER449240 ABB HIER449240, Unitrol UN 0803A-P Module

ABB Module No.: HIER449240, HIER449240

HIER449240 functions:

1. Signal Acquisition – Digital input modules read binary signals (ON/OFF, open/closed) from field devices such as pushbuttons, limit switches, proximity sensors, and contactors, converting them into electrical signals that the controller can process.

2. Control of Field Devices – Digital output modules send binary control signals to actuators such as relays, solenoid valves, motor starters, indicator lamps, and other devices to turn them ON or OFF based on the program logic.

3. Electrical Isolation – They provide isolation between the high-voltage/current field wiring and the low-voltage control system to protect the controller and ensure safety.

4. Voltage Level Adaptation – Support various voltage levels (e.g., 24 V DC, 120 V AC, 230 V AC) to match different types of field equipment and installation standards.