The Allen-Bradley 1771-IK, also cataloged as the 1771IK Encoder/Counter Module Assembly, operates as a dedicated hardware component for high-speed pulse processing and position tracking within Allen-Bradley PLC-5 systems.

Module Configuration & Variants

• 1771-IK: Standard dual-slot encoder/counter module assembly supporting 12-24 VDC input logic and 5 VDC open-collector outputs.
• 1771IK: Equivalent spare hardware identifier denoting the double-slot pulse acquisition module for 1771 universal I/O chassis.

Physical & Electrical Parameters

High-Speed Processing & Deterministic Execution

The module processes high-speed quadrature encoder signals up to 50 kHz, transferring updated position counts across the backplane bus communication velocity architecture every 1.3 ms. Direct internal hardware registers process pulse streams without taxing processor scan cycles. The internal board design maintains firmware flash compatibility across host PLC-5 controllers, optimizing overall I/O density scaling across complex multi-axis motion configurations.

Shipping Package Content

• 1 x 1771-IK Dual-Slot Encoder/Counter Assembly
• 2 x Field Wiring Arm Alignment Keying Bands

Hardware Mounting & Wiring Rules

Dual-Slot Chassis Installation

• Insert keying bands into two adjacent 1771 backplane connectors matching the dual-card guide spacing.
• Slide the double-width assembly smoothly along upper and lower card guides until both rear backplane connectors lock completely into position.

Encoder Signal Shielding and Wiring

• Connect quadrature encoder signals using individually shielded, twisted-pair cables.
• Ground cable shields at a single point on the chassis frame ground to eliminate circulating ground loop currents.
• Maintain physical isolation between encoder signal wiring and high-power AC motor drives or contactor lines.

Technical Operational FAQs

• What maximum input pulse frequency does the 1771-IK support?

  The module processes incoming encoder pulse streams up to a maximum frequency of 50 kHz across its input channels.

• How many I/O slots are required in the 1771 chassis for this assembly?

  The physical footprint of the 1771-IK requires two adjacent slots within a standard 1771 universal I/O chassis.

• What current does the module draw from the 5 VDC backplane bus?

  The assembly draws a continuous operating current of 1.2 A at 5 VDC directly from the backplane power supply.

• What is the update refresh rate of the module internal register data?

  The module updates its internal position counters and transfers data to the processor backplane every 1.3 ms.

• What electrical specification applies to the onboard outputs?

  The module features 5 VDC open-collector outputs rated for a maximum current capacity of 0.5 A per channel.

• Can the module be inserted or removed under backplane power?

  No. Disconnect backplane system power prior to insertion or removal to prevent electrical damage to backplane connector pins.

• What field operating voltage range is required for encoder signals?

  The module input stage is designed to interface with field signals operating within a 12 to 24 VDC voltage window.

• What wire size range is compatible with the field wiring terminals?

  The corresponding field terminal block accepts solid or stranded copper wire sizes ranging from 14 AWG to 22 AWG.