Functional Characteristics

The Toshiba HC422B is a specialized high-speed pulse processing module that bridges the gap between mechanical motion and digital control logic. As part of the PROSEC T and V-series ecosystem, it is designed to capture and process rapid pulse trains that occur too quickly for a standard PLC scan cycle to register. By offloading the counting tasks to the HC422B’s internal hardware, the system ensures that no pulses are missed, regardless of the complexity of the user application program.

The module is equipped with dual independent channels, allowing for the simultaneous monitoring of two separate encoders or frequency-based sensors. Each channel can be configured to operate in multiple modes, including 1-phase counting, 2-phase (quadrature) counting for direction detection, and up/down pulse counting. This versatility makes the HC422B the primary choice for industrial engineers tasked with high-precision positioning, web tension control, and velocity monitoring.

Technical Specifications

The following performance metrics are based on official Toshiba engineering documentation for the HC422B module:

Core Design Features

High-Frequency Pulse Processing

The HC422B utilizes a high-bandwidth input stage capable of receiving signals at frequencies up to 100 kHz. This capability is critical for modern high-resolution rotary encoders used in CNC machinery and high-speed conveyor systems. The module includes adjustable digital filters to suppress high-frequency noise and prevent false counts caused by electrical chattering in field wiring.

Coincidence Output Function

One of the standout features of the HC422B is its hardware-based comparison logic. Users can set target "coincidence" values via the PLC software. When the internal counter reaches the target value, the module can immediately activate a physical output or trigger an interrupt in the CPU. Because this happens at the hardware level, the response time is nearly instantaneous, enabling precise "cut-to-length" or "stop-on-mark" operations that are impossible with standard I/O.

System Integration and Configuration

Integration of the HC422B into a Toshiba controller rack is seamless. The module occupies a single slot and communicates with the CPU via the high-speed backplane. Configuration is performed through Toshiba's standard engineering tools, where parameters such as multiplication factors (x1, x2, or x4 for quadrature signals) and reset conditions are defined.

The module also provides status LEDs on the front panel, offering immediate visual diagnostics for input signal activity and coincidence output status. This helps technicians verify encoder operation and signal phase alignment without the need for an oscilloscope in the field.

Application Areas

The Toshiba HC422B is widely implemented in industries requiring high-speed synchronization and measurement:

• Motion Control: Feedback loops for servo and stepper motor positioning in robotics.

• Textile and Paper Mills: Precise length measurement and winding speed control.

• Packaging and Bottling: High-speed object counting and synchronization of filling heads.

• Energy & Utilities: Processing high-frequency pulses from turbine flow meters for accurate volume calculation.

Installation and Wiring Best Practices

To ensure the highest accuracy, the HC422B should be wired using twisted-pair shielded cables, especially for the pulse input lines. The shield should be grounded at a single point to avoid ground loops. When using differential drivers (RS-422 standard), the module provides superior noise rejection over long distances compared to open-collector wiring.

Before commissioning, it is vital to verify that the external power supply for the encoder matches the voltage requirements of the HC422B's input terminals. Proper termination resistors should be used if the cable runs exceed 10 meters to prevent signal reflection and data corruption.

Conclusion

The TOSHIBA HC422B High-Speed Counter Module is a robust, high-performance solution for demanding industrial pulse-counting tasks. By combining high-frequency response with dual-channel flexibility and hardware-level comparison logic, it empowers Toshiba PROSEC systems to handle the most rigorous motion control and measurement challenges. Its design emphasizes reliability and precision, making it a cornerstone for automation professionals seeking SIL-grade performance in their control architectures.