Allen-Bradley 1771-IM PLC 5 Digital Input Module

Allen-Bradley 1771-IM Digital AC/DC Input Module

Product Introduction

The 1771-IM from Allen-Bradley is a high-quality digital input module designed for the PLC-5 programmable controller series. This I/O module provides eight dedicated input channels. It is specifically built to interface with a variety of field devices, including selector switches, pushbuttons, limit switches, and float switches. A key advantage of this model is its compatibility with both AC and DC power sources. This flexibility makes it a versatile choice for many industrial control applications. Its operating voltage range spans from 184 to 276 volts. Therefore, it easily accommodates nominal 220-240V AC or 240V DC systems. The Allen-Bradley 1771-IM ensures accurate signal detection. It processes input signals with defined delay times for predictable control responses. Additionally, its design includes optical isolation. This feature helps protect the backplane from electrical noise and surges.

Technical Specifications

The 1771-IM module delivers consistent and dependable technical performance. It features eight inputs that receive signals from up to eight different devices. The voltage category is rated for 220 Volts AC/DC. Its AC operating voltage range is from 184 to 276 Volts. Similarly, its DC operating voltage range is also from 184 to 276 Volts. The nominal input current varies. For instance, it draws 2.6 mA at 240V DC. Meanwhile, it draws 3 mA at 220V AC at 50 Hz and 3.5 mA at 220V AC at 60 Hz.

The module has a minimum on-state current of 2.9 mA. In contrast, its maximum off-state current is just 1.0 mA. This low off-state current ensures efficient operation. The maximum off-state voltage is between 92 and 114V AC. Furthermore, the backplane current draw is only 75 mA. This low draw minimizes the load on the power supply. The input signal delays are crucial for timing. The typical AC signal delay from off to on is 20 (+/- 6) ms. The typical DC signal delay from off to on is 10 (+/- 4) ms. For the off transition, the AC delay is 20 (+/- 6) ms, while the DC delay is 20 (+/- 9) ms. The module's power dissipation ranges from a minimum of 0.4 W to a maximum of 2.4 W. Consequently, thermal dissipation ranges from 3.2 to 10.9 BTU/hr.

Mechanical and Environmental Limits

The Allen-Bradley 1771-IM operates reliably in various industrial environments. Its operating temperature range is from 32 to 140 degrees Fahrenheit. Moreover, it can function in conditions with 5% to 95% non-condensing relative humidity. This module is rack-mountable for easy installation. It requires the 1771-WA wiring arm for field wiring connections. This accessory ensures secure and organized terminations.

Installation Guidance

Installing the 1771-IM module is a straightforward process. First, ensure the PLC-5 chassis is powered off. Next, select an available slot in the rack. Carefully slide the module into the selected slot. Press firmly to ensure it seats correctly into the backplane connector. Then, secure the module using the retaining screws. After that, attach the 1771-WA wiring arm to the front of the module. Now, connect your field device wires to the appropriate terminals on the wiring arm. Double-check all connections for accuracy and tightness. Finally, power on the chassis and verify the module's status indicator. This sequence ensures a safe and correct installation.

Packaging List

Each new Allen-Bradley 1771-IM module ships with the following components:

• 1 x 1771-IM Digital AC/DC Input Module

• 1 x User Manual (Quick Start Guide)

• The module is packaged in an anti-static bag for protection.

Please note that the 1771-WA wiring arm is sold separately. Shipping is handled via trusted carriers such as Fedex, UPS, or DHL.

Frequently Asked Questions (FAQ)

1. What is the primary function of the 1771-IM module?
The 1771-IM serves as an interface between field input devices and the PLC-5 processor. It monitors eight discrete signals from switches and sensors, converting them into logic levels for the controller.

2. Can this 1771-IM module operate on both AC and DC voltage?
Yes, absolutely. This specific model is a universal AC/DC input module. It accepts both AC and DC voltages within the 184 to 276-volt range. This eliminates the need for separate modules for AC and DC signals.

3. What is the typical signal delay for this module?
The signal delay depends on the input type. The AC signal delay is typically 20 (+/- 6) ms for both on and off transitions. The DC signal delay is faster at 10 (+/- 4) ms for the on transition and 20 (+/- 9) ms for the off transition.

4. What type of wiring arm is required for the 1771-IM?
This input module specifically requires the 1771-WA wiring arm. This accessory is necessary to make field wiring connections to the module's terminals. It is not included with the module and must be ordered separately.

5. Is the Allen-Bradley 1771-IM compatible with other PLC systems?
The 1771-IM is specifically designed for the Allen-Bradley PLC-5 series. It is not compatible with other PLC platforms like ControlLogix or SLC-500 due to different physical and electrical specifications.