Allen-Bradley 1771-HRA Resolver Excitation Module

Allen-Bradley 1771-HRA Resolver Excitation Module for PLC-5

Product Introduction

The Allen-Bradley 1771-HRA is a dedicated resolver excitation module. It belongs to the PLC-5 series and works specifically with the IMC 120 Motion Control System. This module generates sine and cosine excitation signals. These signals drive the stator windings of resolvers connected to the system. Consequently, it provides accurate position feedback to the motion controller. The 1771-HRA installs in a 1771 I/O chassis slot. It draws its operating power from the 1771-PS7 power supply module. Furthermore, it features a green LED for real-time power status monitoring. The module uses the 1771-CAPR cable for termination panel connections.

Key Technical Specifications

The 1771-HRA delivers a sinusoidal output with precise amplitude control. The minimum amplitude is 6.72 Volts RMS. The maximum amplitude reaches 7.42 Volts RMS. Additionally, it maintains a sine-to-cosine matching accuracy of 0.3% maximum. The output frequency is fixed at 2.5 KHz. The sine-to-cosine phase relationship stays at 90° within ±4.5 minutes. Furthermore, the sine phase offset is 0.45° with a drift of ±5.4 minutes. These specifications ensure accurate resolver excitation for precise position sensing. The module also features a signal delay time of 2 seconds from power-up to output.

Power Requirements and Consumption

The 1771-HRA draws power from the 1771-PS7 power supply module. This supply provides 5V, 15V, and 24V DC through the 1771-CAS cable. The cable connects to the 12-pin Latch and Lock connector on the module. The module's current draw is 340 milliamps at 5.2 Volts DC. It also draws 228 milliamps at 15 Volts DC. Total backplane power consumption is only 0.4 Watts. However, the maximum wattage rating reaches 9.06 Watts. This efficient design minimizes the overall system power budget. The green LED indicator illuminates when power is applied correctly.

Output and Load Characteristics

The 1771-HRA provides robust output capabilities for resolver excitation. Its maximum output inductive load rating is 80 Ohms at 80° phase angle. The output current limit ranges from 0.81 Amps minimum to 0.35 Amps maximum. Signal distortion is exceptionally low at 0.1% THD. The maximum offset voltage is 0.01 Volts DC. These characteristics ensure clean, stable excitation signals. Consequently, the resolver feedback remains accurate and reliable. The module also provides +/- 10 Volt DC analog command outputs. This feature adds versatility for additional control functions.

Installation and Setup Guide

First, ensure the system is powered down completely. Next, locate an available slot in the 1771 I/O chassis. Insert the 1771-HRA module firmly into the slot. Secure it using the chassis locking mechanism. Then, connect the 1771-PS7 power supply using the 1771-CAS cable. Attach the cable to the 12-pin Latch and Lock connector. After that, connect the 1771-CAPR 12-foot cable from the module to the termination panel. Verify all connections are secure. Finally, apply power to the system. The green LED should illuminate to confirm power status. The module will then output excitation signals after the 2-second delay period.

Packaging List

• 1 x 1771-HRA Resolver Excitation Module

• 1 x Installation Instructions Manual

• 1 x 12-pin Latch and Lock connector (pre-attached)

Note: The 1771-PS7 power supply, 1771-CAS cable, and 1771-CAPR termination cable are sold separately.

Shipping Information

We ship all orders via FedEx, UPS, or DHL. The module is packaged in anti-static protective materials. It is then placed in a sturdy shipping box with adequate cushioning. Tracking numbers are provided after dispatch. Processing time is typically 1-2 business days.

Frequently Asked Questions (FAQ)

1. What is the primary function of the 1771-HRA module?
The 1771-HRA generates sine and cosine excitation signals for resolvers in the IMC 120 System. These signals provide accurate position feedback to the motion controller.

2. Which power supply works with the 1771-HRA?
This module draws power from the 1771-PS7 power supply. This supply provides the required 5V, 15V, and 24V DC through a dedicated cable connection.

3. What is the output frequency of the 1771-HRA?
The module outputs a fixed frequency of 2.5 KHz. This frequency is optimized for resolver excitation applications in the IMC 120 System.

4. How long does the module take to output signals after power-up?
The 1771-HRA has a signal delay time of 2 seconds from power-up to output. This delay ensures stable operation before excitation begins.

5. What cable connects the 1771-HRA to the termination panel?
The 1771-CAPR 12-foot cable connects the module to the termination panel. This cable ensures proper signal transmission between the module and resolver feedback devices.