GE Fanuc IC694APU300 High Speed Counter Module

The GE Fanuc IC694APU300 is a high-speed counter module for the RX3i programmable logic controller system. It provides eight independent 32-bit counter channels that can be configured for a variety of high-speed counting applications, including quadrature encoder inputs, up/down counting, and pulse catch. Each channel operates at up to 200 kHz, making it suitable for high-speed motion feedback, flow metering, and position sensing. The module interfaces directly with sensors such as incremental encoders, proximity switches, and pulse generators. The APU300 is part of the RX3i I/O family and mounts in a standard RX3i Universal Backplane.

Technical Specifications

The IC694APU300 operates on a 5 V DC backplane supply with a consumption of 500 mA. Each of the eight channels can be configured for: quadrature encoder (phase A, B, Z), single pulse train (up/down), or direction + pulse. Input frequency: 200 kHz maximum. Input voltage: 24 V DC (sink/source configurable). Input impedance: 3.9 kΩ. Count range: 32-bit (0 to 4,294,967,295) or signed (-2,147,483,648 to 2,147,483,647). The module includes 8 digital outputs (24 V DC, 0.5 A) that can be associated with counter presets or under/over limits. Configuration is done via Proficy Machine Edition software. Dimensions: 140 mm × 32 mm × 110 mm. Weight: 0.3 kg. Operating temperature: 0°C to 60°C. Storage: -40°C to 85°C. Protection rating: IP20.

Key Features

• 8 independent 32-bit high-speed counter channels

• 200 kHz maximum input frequency

• Configurable as quadrature encoder, up/down, or direction/pulse

• Built-in digital outputs per channel for limit switching

• Supports encoder index (Z) pulse for homing

• Programmable count direction, preset, and reset

• Diagnostic LEDs for each channel and module status

• Compatible with RX3i backplane and CPUs

Counter Modes and Applications

In quadrature encoder mode, the module decodes A, B, and Z signals to determine position and direction. In up/down mode, it counts pulses from two separate sources. In direction/pulse mode, one input provides pulses and another provides direction. Each channel has two associated digital outputs that can be triggered by preset values, underflow, overflow, or index. Typical applications include position feedback for stepper or servo axes, flow meter totalization, high-speed part counting on conveyors, and measuring shaft speed. The high 200 kHz frequency allows operation with high-resolution encoders at high rotational speeds.

Configuration and Programming

Configuration is performed in Proficy Machine Edition software. Each channel is individually set for mode, input filtering, count limits, and output behavior. The counter values are read as 32-bit integers in the PLC’s input table. The outputs are controlled by the PLC’s output table. The module supports hardware preset (using an input) and software preset. The module’s firmware can be updated via the backplane. Ladder logic instructions are available to enable/disable counters and to reset or preset values.

Installation and Wiring

Install the module in any I/O slot of an RX3i backplane (IC695CHSxxx). Use the removable terminal block (included) for field wiring. For each channel, connect signal A, B (if quadrature), and Z (optional) to the input terminals. For up/down mode, connect two signal wires. The module requires 24 V DC for field inputs; supply this via external power. Output terminals are available for each channel; use an external 24 V DC supply for outputs. Shielded twisted-pair cable is recommended for encoder connections. Ground the shield at the panel end. After wiring, configure the module in Proficy Machine Edition.

Maintenance and Diagnostics

LEDs: green for module power, green flashing for communication, yellow per channel for input activity, and red for fault. If a red LED is lit, check the module configuration and wiring. No user-serviceable parts. Keep the module free from dust.

Environmental and Compliance

The IC694APU300 is CE and UL certified, RoHS compliant. Operating temperature: 0-60°C. Humidity: 5-95% non-condensing. Vibration: 2g (10-55 Hz). IP20.

Conclusion

The GE Fanuc IC694APU300 high-speed counter module adds eight high-frequency counting channels to the RX3i PLC system. Its versatile modes and built-in outputs make it ideal for motion control, flow measurement, and high-speed counting applications.