OVERVIEW

Official designation: Allen-Bradley 1775-LX (PLC-3, Expansion Module)

Role/Application: This communication adapter module occupies one chassis slot to expand the PLC-3 system's backplane (EBUS) capabilities, enabling remote I/O and increasing I/O connection capacity.

KEY SPECS SUMMARY

Power: 5 to 15 V DC

Interfaces / Ports: Four 50-pin EBUS connectors

Indicators: LED signals errors in communication

Operating Temp: 0 to 60 degrees C

Platform / Compatibility: PLC-3 processor system, single slot chassis mount

Limit: Backplane current draw 5 A from 5V DC circuit

Lifecycle: Discontinued/Obsolete

FREQUENTLY ASKED QUESTIONS

Technical Specifications:

Q: What are the two primary DC power circuits the 1775-LX module draws current from?

A: The module draws power from the 5V DC and 15V DC power supply circuits on the chassis backplane.

Wiring & Installation:

Q: How many 50-pin connectors are used on the 1775-LX module for expansion bus access?

A: The expansion module provides access to the EBUS via four 50-pin connectors on its front edge.

Troubleshooting & Compatibility:

Q: What current capacity limits should be observed for the 1775-LX backplane power draw?

A: The module draws a maximum of 5 A from the 5V DC circuit and 80 mA from the 15V DC circuit.

Replacement & Upgrades:

Q: What current generation Allen-Bradley system is the recommended migration path from the PLC-3 platform?

A: The recommended migration path is the ControlLogix platform utilizing modules like the 1756-RIO for RIO network connection.