PRODUCT INFORMATION
Product Overview
The Allen-Bradley 1771-IJ is a PLC-5 encoder and counter module designed for positioning input operations. It provides an interface between field encoders and the 1771 system rack backplane. The unit accepts single-ended or differential incremental encoder signals alongside single-channel field devices. An external 5 VDC power supply is required to maintain compatibility with standard TTL input signals.
This dual-slot module mounts directly into an Allen-Bradley 1771 I/O chassis. It draws 1.2 A of current from the backplane power supply. Field wiring terminates at a compatible 1771-WA or 1771-WB wiring arm. The hardware processes input frequencies up to 50 kHz with a module update period of 1.3 ms. Open-collector outputs supply up to 0.5 A per channel at 5 VDC.
TECHNICAL DATA
Technical Specifications
| Parameter | Specification |
|---|
| Module Type | Positioning I/O Encoder/Counter Module |
|---|
| Slot Width | 2 Module Slots |
|---|
| Backplane Current Draw | 1.2 A |
|---|
| Input Signal Compatibility | 5 V TTL Single-Ended or Differential Incremental Encoder, Single-Channel Device |
|---|
| Maximum Input Frequency | 50 kHz |
|---|
| Output Rating | 5 VDC Open-Collector, 0.5 A per output |
|---|
| Module Update Period | 1.3 ms |
|---|
| Compatible Wiring Arms | 1771-WA, 1771-WB |
|---|
| Typical AC Signal Delay (Off) | 24 ms (+/- 10 ms) |
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| Typical DC Signal Delay (Off) | 20 ms (+/- 9 ms) |
|---|
| Mounting | 1771 I/O Chassis Rack Mount |
|---|
TECHNICAL INFORMATION
Features
- Accepts 5 V TTL single-ended or differential incremental encoder inputs.
- Handles input signal frequencies up to 50 kHz.
- Delivers an internal module update period of 1.3 ms.
- Provides 5 VDC open-collector outputs rated at 0.5 A per output.
- Installs into two module slots of a standard 1771 chassis.
- Draws 1.2 A of operating current from the 1771 backplane.
TECHNICAL INFORMATION
Applications
- Interfacing incremental optical encoders with Allen-Bradley PLC-5 control systems.
- High-speed pulse counting and frequency tracking up to 50 kHz.
- Position feedback acquisition using single-ended or differential TTL devices.
TECHNICAL INFORMATION
Connections / Interfaces
- Field wiring interface via 1771-WA or 1771-WB wiring arms.
- Dual-slot direct connection to the 1771 chassis backplane.
- Field input terminals for external 5 VDC power supply connection.
TECHNICAL INFORMATION
Installation Guidelines
- Mount the module into two adjacent module slots within a 1771 I/O chassis.
- Disconnect all backplane and external field power before inserting the module.
- Terminate field signal lines onto a 1771-WA or 1771-WB wiring arm.
- Connect an external 5 VDC supply to maintain TTL input voltage levels.
TECHNICAL INFORMATION
Configuration Guidelines
- Assign module rack addressing using standard PLC-5 I/O chassis addressing rules.
- Configure input channel modes for single-ended or differential encoder formats.
TECHNICAL INFORMATION
Compatibility
- Mounts into Allen-Bradley 1771 I/O chassis assemblies.
- Operates within Allen-Bradley PLC-5 control architectures.
- Mates with 1771-WA and 1771-WB wiring arms.
TECHNICAL INFORMATION
Lifecycle / Replacement Information
- Designated as an earlier model within the Allen-Bradley PLC-5 platform.
TECHNICAL RESOURCES
Documentation
COMPATIBILITY
Compatibility & Replacement
COMPATIBLE MODELSMounts into Allen-Bradley 1771 I/O chassis assemblies. Operates within Allen-Bradley PLC-5 control architectures. Mates with 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
How many chassis slots does the 1771-IJ module occupy?
The 1771-IJ occupies two module slots in an Allen-Bradley 1771 I/O chassis.
What maximum input frequency does the 1771-IJ support?
The module supports maximum input frequencies up to 50 kHz.
Which wiring arms connect to the 1771-IJ?
The module connects to field wiring using either 1771-WA or 1771-WB wiring arms.
What is the indicative market reference price for the 1771-IJ?
Observed market reference pricing is approximately 189 USD for a refurbished unit. This figure is indicative market reference pricing only and is not a final quotation.
