Digital AC/DC Input Module | Allen-Bradley 1771-IMD/B

Overview

The Allen-Bradley 1771-IMD/B is a versatile digital input module designed to support both AC and DC signals. It provides reliable monitoring of 16 input channels and is suitable for diverse control applications requiring fast, accurate signal detection and robust electrical performance.

Technical Specifications

• Manufacturer: Allen-Bradley

• Model & Part Number: 1771-IMD/B

• Category: PLC Modules

• Number of Inputs: 16

• Nominal Input Voltage: 220V DC, 220V AC at 50–60 Hz

• Nominal Input Current: 0.6 mA at 220V DC, 9.9 mA at 220V AC (50 Hz), 10.4 mA at 220V AC (60 Hz)

• On-State Voltage Range: AC 184–250V, DC 166–230V

• Maximum Off-State Voltage: 92V AC or DC

• Maximum Off-State Current: 3 mA at 92V AC, 0.25 mA at 92V DC

• Minimum On-State Current: 8.7 mA at 184V AC (50 Hz), 0.43 mA at 166V DC

• Input Signal Delay: OFF to ON: 15 ± 8 ms; ON to OFF: 172 ± 56 ms

• Input Impedance: 0.15 μF capacitor in parallel with 21.2 kΩ at 50 Hz; 370 kΩ resistor in series with 1 kΩ

• Backplane Current: 250 mA at 5V DC ±5%

• Power Dissipation: Minimum 1.3 W, Maximum 5.8 W

• Thermal Dissipation: Minimum 4.5 BTU/hr, Maximum 19.8 BTU/hr

• Operating Temperature: 0–60°C (32–140°F)

Applications

• Monitoring AC and DC signals in PLC control systems

• Input interface for machinery and process automation requiring precise digital detection

• Systems where rapid and reliable signal processing is critical

FAQ

Q: How many input channels does the 1771-IMD/B support?
A: The module supports 16 digital input channels for AC or DC signals.

Q: What is the acceptable input voltage range?
A: AC: 184–250V, DC: 166–230V, with off-state voltage up to 92V.

Q: Can it handle fast signal changes?
A: Yes, the OFF to ON delay is 15 ± 8 ms, and the ON to OFF delay is 172 ± 56 ms for both AC and DC inputs.

Q: What are the environmental operating limits?
A: The module operates within 0–60°C (32–140°F), suitable for standard control cabinet installations.