Configured for high-speed expansion bus interfacing in PLC-3 controller racks, the Allen-Bradley 1775-LX (1775-LX Communication Adapter Module) provides direct physical/electrical execution for inter-chassis data link routing and local signal adaptation.

Sub-System Hardware Matrix

• 1775-LX: Base expansion adapter module engineered for PLC-3 controller chassis data bus extended routing.
• 1775LX: Spare assembly designation referencing equivalent backplane pin configuration and line interface hardware.

Electrical & Physical Specifications

Deterministic Network Data Handling

The adapter uses integrated control logic to maintain overall backplane bus communication velocity across expansion chassis drops. Built-in signal conditioning buffers protect transmission integrity, ensuring process image updates execute with low latency without overloading primary CPU execution sweeps.

Standard Delivery Hardware

• 1 x Allen-Bradley 1775-LX Communication Adapter Module
• 2 x 75 ohm line termination resistors

Hardware Installation Rules

• Chassis Isolation Procedure
  • De-energize all primary 115/230 V AC power supplies servicing the chassis prior to hardware insertion or extraction.
• Bus Termination Installation
  • Place 75 ohm termination resistors across outer communication cable endpoints to eliminate high-frequency transmission reflections.
• Voltage Transformer Selection
  • Ensure system jumpers match local supply inputs (115 V AC or 230 V AC nominal) before applying power to prevent fuse damage.
• Cable Separation Standards
  • Run low-voltage communications lines in separate conduit paths at least 30 cm away from three-phase AC power lines.

Technical System FAQs

• What is the main function of the 1775-LX adapter module?

  It coordinates data transfers between PLC-3 main racks and external expansion chassis over dedicated communication paths.

• What galvanic isolation rating applies to the module circuit design?

  The internal isolation barrier is rated for up to 1500 V AC to protect logic circuits from field electrical surges.

• Are terminal resistors mandatory for operational stability?

  Yes, 75 ohm resistors must be terminated at line ends to maintain correct signal impedance across data links.

• Can this module be installed while the backplane is powered up?

  No, insertion or extraction under active power can cause backplane voltage spikes and hardware damage.

• What power input thresholds apply to the primary power circuit?

  The module operates on 115 V AC or 230 V AC (+/- 15%) line inputs with a typical consumption of 40 W.

• How does this unit affect backplane bus communication velocity?

  The hardware includes buffered data channels that maintain high-speed bus velocity across multi-rack topologies.

• What storage temperature range is supported by the hardware?

  The module can be stored safely in unpowered environments ranging from -40 deg C to +85 deg C.

• What is the maximum humidity limit during operation?

  Operating environments must not exceed 95% relative humidity under non-condensing thermal conditions.