Allen-Bradley 1746-HSCE Overview
The Allen-Bradley 1746-HSCE is a high-speed counter module designed for the SLC 500 PLC platform. It provides precise counting and motion detection capabilities for demanding industrial applications. This module supports bidirectional counting and includes inputs A, B, and Z, compatible with 5VDC differential and 0-5VDC single-ended signals. With a maximum input frequency of 50 kHz in Sequencer mode, it handles fast processes effectively.
Engineers use this module for totalizing, motion detection, and other tasks requiring rapid discrete input processing. It fits into any SLC 500 chassis, either locally or remotely, making it versatile for various system architectures.
Key Technical Specifications
The 1746-HSCE operates on a single counting channel and draws 320 mA from the 5V backplane supply. It accepts a minimum pulse width of 10 microseconds and a pulse separation of 4.5 microseconds. The module supports a maximum cable length of 305 meters (1000 feet) with Belden 9503 or equivalent cable.
It includes four open-collector outputs, each rated for 16 mA at 4.5V DC, 40 mA at 10V DC, and 125 mA at 30V DC. The operating temperature range spans 0°C to +60°C, and the storage range extends from -40°C to +85°C. The module provides 1500V isolation voltage and updates every 4.8 milliseconds.
Configurable Operating Modes
The 1746-HSCE can operate in three distinct modes: Range, Rate, and Sequencer. Each mode optimizes the module for different counting requirements. In Sequencer mode, the maximum input frequency reaches 50 kHz, while Range and Rate modes support up to 32.767 kHz. This flexibility allows engineers to tailor the module to their specific process needs.
The module also includes a limit switch input with ON-state voltage ranges of 3.8-5.4VDC, 9.4-16.5VDC, and 16.5-30VDC, corresponding to 5V, 12V, and 24V nominal supplies. This input adds versatility for integrating external sensors or switches.
Installation and Wiring Best Practices
Proper installation ensures reliable operation. Mount the 1746-HSCE in any available slot of the SLC 500 chassis, either adjacent to the CPU or via a remote communication adapter. Use the recommended Belden 9503 cable to maintain signal integrity over long distances, up to 305 meters.
For differential wiring, connect the A, B, and Z inputs with twisted-pair cables to minimize noise. For single-ended wiring, ensure a solid ground reference. The module uses a 1746-RT25G I/O connection, so verify compatibility with your terminal block.
Set the output voltage switch according to your load requirements: turn Switch 2 on for 4.5-10V DC operation, or off for 10-30V DC. This adjustment ensures the open-collector outputs deliver the correct ON-state current.
Diagnostics and Maintenance
The 1746-HSCE includes built-in diagnostic LEDs for CPU faults, error codes, and status indication. An internal status word in the input data file provides real-time monitoring. Regularly inspect these indicators to catch issues early and reduce downtime.
Operate the module within the specified temperature and humidity ranges (5-95% non-condensing) to maintain accuracy. Install it in a NEMA-rated enclosure to protect against industrial contaminants. Routine checks of wiring and connectors help prevent intermittent faults.
Applications and Value
This module excels in factory automation tasks like packaging, material handling, and conveyor control. Its high-speed counting capability also supports process automation scenarios requiring precise rate monitoring. The combination of bidirectional counting, multiple modes, and robust diagnostics makes the 1746-HSCE a practical choice for engineers seeking reliable performance.
For procurement teams, the Allen-Bradley 1746-HSCE offers a proven solution with clear specifications, ensuring compatibility with existing SLC 500 systems. Its moderate power draw and flexible wiring options simplify integration. Whether upgrading a legacy line or designing a new system, this module delivers dependable counting functionality.