PRODUCT INFORMATION
Product Overview
The Allen-Bradley 1771-HRA is a resolver excitation module designed for the PLC-5 control platform. It provides specialized resolver interface capabilities within a standard 1771 I/O chassis architecture. Operating as an excitation source and driver module, it accepts high-speed feedback for precise motion tracking. The unit draws power from an external 1771-PS7 power supply or the backplane. Its maximum power dissipation reaches 9.06 Watts under full operating loads.
This module occupies two slots per ES in a compatible 1771 I/O chassis assembly. It features a backplane current draw rating of 1.7 Amperes. Internal current ratings include 340 milliamps at 5.2 Volts DC and 228 milliamps at 15 Volts DC. The module supports high-speed signal processing with a differential input frequency up to 250 kilohertz. Output commands provide plus-or-minus 10 Volt DC analog control signals.
TECHNICAL DATA
Technical Specifications
| Parameter | Specification |
|---|
| Module Type | Resolver Excitation Module |
|---|
| Backplane Current Draw | 1.7 A |
|---|
| Current Rating at 5.2V DC | 340 mA |
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| Current Rating at 15V DC | 228 mA |
|---|
| Maximum Power Dissipation | 9.06 W |
|---|
| Power Supply Reference | 1771-PS7 |
|---|
| Slot Width | 2 Slots Per ES |
|---|
| Analog Outputs | +/- 10 V DC Command |
|---|
| Max Input Frequency | 250 kHz Differential Input |
|---|
| Module Update Period | 2 ms/axis |
|---|
| Pulse Capture Time | 50 to 9.999 microseconds |
|---|
| Fuse Voltage Rating | 120 V |
|---|
| Compatible Wiring Arms | 1771-WA, 1771-WB |
|---|
TECHNICAL INFORMATION
Features
- Delivers dual-slot resolver excitation and driver functionality for PLC-5 systems.
- Provides +/- 10 Volt DC analog command outputs for velocity or position drive loops.
- Supports differential input signals with maximum operating frequencies up to 250 kHz.
- Achieves rapid signal tracking with a module update period of 2 milliseconds per axis.
- Captures high-speed position feedback pulses within a 50 to 9.999 microsecond range.
- Features a 120 Volt fuse voltage rating for internal circuit protection.
TECHNICAL INFORMATION
Applications
- PLC-5 closed-loop motion control systems requiring resolver position feedback.
- Industrial machinery positioning interfaces utilizing +/- 10V analog velocity commands.
- High-speed axis position monitoring in legacy Allen-Bradley 1771 automation systems.
TECHNICAL INFORMATION
Connections / Interfaces
- Field wiring terminates via compatible Allen-Bradley 1771-WA or 1771-WB wiring arms.
- Provides differential input terminals capable of receiving frequencies up to 250 kHz.
- Delivers +/- 10 Volt DC analog output signals directly to compatible motor drives.
- Connects to the PLC-5 backplane across two contiguous 1771 chassis slots.
TECHNICAL INFORMATION
Installation Guidelines
- Seat the module firmly into two adjacent slots of an Allen-Bradley 1771 I/O chassis.
- Ensure all power to the 1771 chassis is disconnected before inserting or removing the hardware.
- Secure field signal lines using the specified 1771-WA or 1771-WB wiring arm assembly.
- Verify adequate backplane power capacity to support the 1.7 Ampere backplane current load.
TECHNICAL INFORMATION
Configuration Guidelines
- Configure motion parameters according to the 2 millisecond per axis module update rate.
- Tune the +/- 10 Volt DC analog output scaling to match connected drive command inputs.
- Set input capture parameters to align with the 50 to 9.999 microsecond pulse capture timing.
TECHNICAL INFORMATION
Compatibility
- Operates in Allen-Bradley 1771 I/O chassis alongside PLC-5 programmable controllers.
- Compatible with Allen-Bradley 1771-PS7 power supply modules.
- Interfaces with field wiring through 1771-WA and 1771-WB wiring arms.
TECHNICAL RESOURCES
Documentation
COMPATIBILITY
Compatibility & Replacement
COMPATIBLE MODELSOperates in Allen-Bradley 1771 I/O chassis alongside PLC-5 programmable controllers. Compatible with Allen-Bradley 1771-PS7 power supply modules. Interfaces with field wiring through 1771-WA and 1771-WB wiring arms.
Verify compatibility against the exact Part Number, revision and manufacturer documentation before ordering.
PART VERIFICATION
Before You Order
Industrial automation parts can share similar model names, suffixes and revisions. Confirm the complete manufacturer Part Number before purchase.
01Check Part NumberMatch the complete ordering code on the existing unit.
02Confirm RevisionCheck suffix, hardware or firmware when applicable.
03Send a Label PhotoWe can review a clear label photo when identification is uncertain.
ORDERING PROCESS
From RFQ to Dispatch
1Submit Part Number2Verify Product Identity3Confirm Stock & Condition4Issue Quotation5Dispatch & Tracking
PRODUCT FAQ
Frequently Asked Questions
What chassis space does the Allen-Bradley 1771-HRA require?
The 1771-HRA occupies two adjacent slots per ES in a standard Allen-Bradley 1771 I/O chassis.
Which wiring arms connect to the 1771-HRA module?
The module is compatible with both Allen-Bradley 1771-WA and 1771-WB field wiring arms.
What is the market reference price for the 1771-HRA?
Observed market reference pricing spans from $189.00 to $390.00 depending on condition. These figures are indicative market reference pricing only and are not a final quotation.
