Product Summary
The 1771-HRA is a critical resolver excitation module from the Allen-Bradley PLC-5 series. It generates precise sine and cosine signals to excite the stator of an IMC 120 resolver feedback system. This module provides accurate position data to the controller, ensuring smooth motion control. It draws power from the 1771-PS7 supply and works with the IMC 120. The 1771-HRA delivers an output frequency of 2.5 KHz for reliable operation.
Why Choose the 1771-HRA for Your System?
Procurement managers need a module that matches exact system requirements. The 1771-HRA resolver excitation module fits perfectly into a 1771 I/O chassis slot. It requires a specific 1771-PS7 power supply to function correctly. This module provides sine wave amplitudes from 6.72V RMS minimum to 7.42V RMS maximum. The sine-cosine matching amplitude is a tight 0.3% maximum. This ensures highly accurate signal generation for your IMC 120 system.
Application engineers value the module's precise signal integrity. It offers a maximum offset voltage of just 0.01V DC. The total harmonic distortion remains under 0.1%. This clean signal minimizes position errors in critical automation tasks. The update period for each axis is a fast 2 ms. You get reliable performance from the power-up, with a maximum signal delay of only 2 seconds.
Expert Technical Performance Review
The 1771-HRA maintains a stable sine-to-cosine phase relationship at 90 degrees. This stays consistent for 4.5 minutes of operation. The sine phase offset is just 0.45 degrees. The sine drift is minimal at plus or minus 5.4 minutes. These tight tolerances define a premium resolver driver component.
Its maximum wattage rating is only 9.06 Watts. This keeps thermal load low inside the control cabinet. The module draws a backplane current of 1.7 Amperes. Power consumption on the backplane itself is just 0.4W. The output inductive load can reach a maximum of 80 Ohms. The output current limit ranges from 0.35A minimum to 0.81A maximum.
Installation and Integration Guide
First, mount the 1771-HRA into a free 1771 I/O chassis slot. Use the 1771-WA wiring arm for secure field wiring connections. Connect the 1771-PS7 power supply using the specified 1771-CAS cable. This cable attaches to the 12-pin latch and lock connector on the module. Then, use the 1771-CAPR 12-foot cable to link the module to the termination panel.
Always check for the green LED indicator light after power-up. This confirms the module is receiving power correctly. The module provides outputs that include a plus or minus 10 Volt DC analog command. You will need two slots per ES module for full configuration. The pulse capture time ranges from 50 to 9.999 microseconds. Follow all safety protocols during installation.
