Allen-Bradley 1756-HSC ControlLogix High Speed Counter Module

Description

The Allen-Bradley 1756-HSC is a ControlLogix high-speed counter module designed for high-speed pulse counting, frequency measurement, and encoder input processing in industrial automation systems. The 1756-HSC counts incoming pulses using either Counter or Frequency operational modes and returns values as accumulated counts or calculated frequencies. Operating through a Producer/Consumer network model, it performs hardware-driven output evaluations independently from controller scans, enabling fast response times. The module is compatible with incremental encoders, 3-wire DC proximity sensors, and photoelectric sensors. It operates within the ControlLogix system chassis and supports removal and insertion under power (RIUP).

Features

• Features three Counter modes (Counter, Encoder x1, Encoder x4) and three Frequency modes (Rate Measurement, Period Rate, Continuous Rate).
• Includes four hardware-driven, isolated onboard outputs capable of sourcing up to 1 A DC at 30V DC with response times under 50 microseconds.
• Provides real-time manipulation of Preset and Rollover values on-the-fly via output tags when using the HSC Data-extended communication format.
• Offers four Z-input storage modes: Store and Continue, Store/Wait/Resume, Store/Reset/Wait/Start, and Store/Reset/Start.
• Supports direct chassis placement and remote chassis operation over EtherNet/IP or ControlNet networks.
• Supports Removal and Insertion Under Power (RIUP) for module maintenance without disrupting system backplane power.

Applications

• High-speed pulse counting and position monitoring with quadrature encoders.
• Flowmeter rate and pulse measurement.
• Turbine speed monitoring and frequency calculations.
• High-speed part sensing, sorting, and packaging automation.

Technical Specifications

Connections/Interfaces

Installation Guidelines

• Enclosure Requirements: Install open-type equipment inside an enclosure suitable for specific environmental conditions to prevent personal injury from live parts.
• Wiring and Cable Shielding: Recommended cable type is Belden 8761 shielded wire. Connect ground drain wire to a chassis mounting tab designated as a functional signal ground.
• Electrostatic Discharge (ESD): Wear an approved grounding wriststrap and handle the module using static-safe precautions.
• RTB Assembly: Key the Removable Terminal Block (RTB) using keying bands to prevent incorrect connection. Ensure field-side power is removed before wiring.
• Conductor Sizing: When using 1756-TBCH, do not wire more than two 0.33...1.3 mm2 (22...16 AWG) conductors on any single terminal. For 1756-TBS6H, connect only one conductor per terminal.

Compliance and Certifications

• North American Hazardous Location Approval: Class I Division 2, Groups A, B, C, D
• Pollution Degree 2, Overvoltage Category II (IEC 60664-1)
• Group 1, Class A Equipment (IEC/CISPR 11)