PRODUCT INFORMATION
Product Overview
The Allen-Bradley 1771-IJC PLC-5 Encoder Input Module tracks pulse signals from encoders, beam counters, and switches. It can make local decisions based on the total pulse accumulation. The module also shares count totals with the processor for system calculations or display. Communication is supported via single-transfer programming in local chassis and block transfer programming in any chassis.
The module handles 5V TTL single-ended or differential signals at frequencies up to 50 kHz. It provides two 5V DC open-collector outputs rated at 0.5 A each. It occupies two slots in any 1771 chassis and draws 1.2 A backplane current. Field devices connect using two 12-terminal gold-plated 1771-WB field-wiring arms. An external 5V DC power supply delivering 140 mA with minimal ripple is required.
TECHNICAL DATA
Technical Specifications
| Parameter | Specification |
|---|
| Backplane Current | 1.2 Amperes |
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| Category | PLCs |
|---|
| Inputs | 5 Volts TTL Single-Ended or Differential Incremental Encoder or Single-Channel Device |
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| Max Input Frequency | 50 Kilohertz |
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| Model Status | Earlier Model |
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| Module Type | Positioning I/O Modules |
|---|
| Module Update Period | 1.3 Milisecond |
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| Outputs | 5 Volts DC Open- Collector 0.5 Ampere Per Output |
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| Product Line | PLC 5 |
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| Slots | 2 Slots |
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| Typical AC Signal Delay (Off) | 24 (+/- 10) ms |
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| Typical DC Signal Delay (Off) | 20 (+/- 9) ms |
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| Weight | 1.69 lbs (0.77 kg) |
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| Wiring Arm | 1771-WB |
|---|
TECHNICAL INFORMATION
Features
- Accepts 5V TTL single-ended or differential inputs from encoders and switches.
- Detects maximum input pulse frequencies up to 50 kilohertz.
- Features two 5V DC open-collector outputs rated at 0.5 amperes per output.
- Occupies two module slots within any standard 1771 I/O chassis.
- Provides a fast internal module update period of 1.3 milliseconds.
- Supports both block transfer programming and local single-transfer programming.
TECHNICAL INFORMATION
Applications
- Encoder pulse tracking and count accumulation in Allen-Bradley PLC-5 control systems.
- Input signal monitoring from optical beam counters and mechanical limit switches.
- Direct high-speed pulse acquisition requiring local output control decisions.
TECHNICAL INFORMATION
Connections / Interfaces
- Connects field wiring through two 12-terminal gold-plated 1771-WB wiring arms.
- Field input devices must reside within 40 cable feet of the module.
- Use Belden 8761 cable for signal frequencies below 20 kilohertz.
- Use Belden 9182 cable for signal frequencies up to 50 kilohertz.
TECHNICAL INFORMATION
Installation Guidelines
- Install the two-slot module into any compatible Allen-Bradley 1771 I/O chassis.
- Disconnect all power from the chassis backplane before inserting or removing the module.
- Remove power from the wiring arm before servicing or replacing hardware.
- Supply external 5V DC at 140 mA with less than 50 mV ripple peak-to-peak.
TECHNICAL INFORMATION
Configuration Guidelines
- Configure module data exchange using block transfer programming across local or remote racks.
- Execute single-transfer programming when the module is installed in a local I/O chassis.
- Confirm field input devices can deliver at least 16 mA drive current.
TECHNICAL INFORMATION
Compatibility
- Allen-Bradley 1771 I/O chassis systems.
- Allen-Bradley PLC-5 programmable logic controller platforms.
- Allen-Bradley 1771-WB 12-terminal field-wiring arms.
TECHNICAL INFORMATION
Lifecycle / Replacement Information
- The 1771-IJC is an earlier model within the 1771 product line.
- Check system requirements before sourcing hardware for legacy PLC-5 architectures.
TECHNICAL RESOURCES
Documentation
COMPATIBILITY
Compatibility & Replacement
COMPATIBLE MODELSAllen-Bradley 1771 I/O chassis systems. Allen-Bradley PLC-5 programmable logic controller platforms. Allen-Bradley 1771-WB 12-terminal field-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 is the primary function of the Allen-Bradley 1771-IJC module?
It tracks input pulses from encoders, optical beam counters, and switches in 1771 systems.
How many chassis slots does the 1771-IJC occupy?
The 1771-IJC module occupies two module slots in any 1771 I/O chassis.
Which field wiring cables are recommended for signal transmission?
Use Belden 8761 below 20 kHz and Belden 9182 for frequencies up to 50 kHz.
What is the reference market price for the 1771-IJC?
Observed market reference pricing is approximately $179.00 USD. This is an indicative market reference price only, not a final quotation.
