45C44 is a dual 24 VAC/DC universal digital input module for Reliance Electric (now Rockwell Automation) AutoMate 40E and AutoMax PLC systems. It connects field devices such as pushbuttons, limit switches and proximity sensors, and converts external 24 VAC or DC signals into standard logic signals for the PLC backplane. This model has been discontinued. Currently only used units, refurbished products and new old stock are available for maintenance and replacement of legacy automation systems.

45C is the unified prefix for I/O modules of AutoMate 45C series. 44 stands for dual 24 VAC/DC input module. Models with suffix A, B, C or D are revised hardware versions, and all versions are fully interchangeable.

Module Type: Dual galvanically isolated digital input module. Channels: 2 independent and electrically isolated channels. Rated Input Voltage: 24 VAC/DC, DC operating range 10 V to 30 V. AC Operating Frequency: 48 Hz to 63 Hz. Turn-on Threshold: minimum 10 VDC, minimum 18 VAC. Turn-off Threshold: maximum 5 VDC, maximum 8 VAC. Isolation Voltage: 2500 V RMS between field side and logic side. Indicators: Two LEDs per channel. Green LED for input power status, yellow LED for logic signal status. Bus Interface: 45C dedicated backplane bus. Power Dissipation: approximately 0.2 W per channel, total power consumption no more than 0.5 W. Installation: Occupies one standard slot of 45C series rack. Weight: approximately 0.15 kg. Operating Temperature: 0°C to 55°C. Operating Humidity: 10% to 90% RH, non-condensing. Certification: Compliant with UL and CE standards.

Two status LEDs are equipped for each channel on the front panel to indicate input power and logic signal respectively. The rear edge connector matches 45C1 standard I/O rail. Complete field wiring according to terminal definitions. It supports both 24 VAC and DC connection modes, and all common terminals shall be connected to system ground. The module has no independent communication port. It exchanges data with the main controller via the rack backplane bus, and no extra address or parameter setting is required.

It accepts both 24 VAC and DC input signals, compatible with mainstream sensors and switching devices in industrial sites. Electrical isolation is designed between channels as well as between field circuits and internal logic circuits, which suppresses electromagnetic interference and protects the PLC system. Two channels work independently, so the fault of one channel will not affect the other. Hierarchical LED indicators clearly show operating status for convenient on-site commissioning and troubleshooting. Low power consumption makes it suitable for cabinets with dense I/O layout. It is fully compatible with legacy modules of the same series, so no wiring or program modification is needed after replacement.

It is used for replacing faulty modules and routine maintenance of AutoMate 40E and AutoMax legacy control systems. It collects signals from 24 VAC/DC powered pushbuttons, limit switches, proximity sensors and other field devices. It is widely applied to renovation of old production lines in automotive, metallurgy, papermaking, water treatment and other industries, and the original 24V signal circuits can be retained. It is ideal for dual digital input occasions with mixed AC and DC signals and high requirements for electrical isolation.

Cut off the main power of the rack before installation or removal. Hot swap is strictly prohibited. Insert the module into the rail slot steadily and fix it firmly. Complete wiring in accordance with terminal specifications and tighten terminals to avoid poor contact. The module works normally after power on, and corresponding LEDs will light up when signals are received. Check LED status regularly during daily operation, and inspect power supply, wiring and front-end devices once abnormalities occur. Clean dust on the module and rail with dry compressed air every month. Keep the operating environment well ventilated and dry, and stay away from strong interference sources such as inverters and motors. If LEDs stay off, check 24V power supply, wiring and external switches in sequence. If false triggering occurs, verify grounding performance or use shielded cables. Always cut off power during maintenance. Do not disassemble the module without permission. Disconnect the power supply and take moisture and dust prevention measures during long-term shutdown.