Allen-Bradley 1734-VHSC5 POINT I/O Very High Speed Counter Module

The Allen-Bradley 1734-VHSC5, also cataloged as the 1734-VHSC5 Very High Speed Counter Module, operates as a dedicated hardware component for high-frequency pulse counting and encoder signal processing within Allen-Bradley POINT I/O systems.

Hardware Specifications

Deterministic Backplane Communication and I/O Density Scaling

• Backplane Bus Velocity: Interfaces with the POINT I/O backplane via a high-speed serial bus, delivering real-time pulse registration and frequency evaluation to the primary controller without network transmission delays.
• I/O Density Scaling: Constructed in an ultra-compact form factor to allow high-density mounting on standard 35 mm DIN rails, scaling system channel capacity while minimizing control panel footprint.
• EtherNet/IP Integration: Maps counter values, frequency measurements, and status flags directly into controller tags over EtherNet/IP adapter modules with configurable Requested Packet Interval (RPI) timing down to 1.0 ms.
• Firmware Flash Compatibility: Supports field firmware flash operations over the backplane bus to verify consistent execution routines and operational parity across system revisions.

Frequently Asked Questions

Q: Can the 1734-VHSC5 module be inserted or removed under power (RIUP)? A: Hot-swapping is permitted only when backplane power is isolated or when operating in non-hazardous location class conditions. Physical keying on the terminal base must be verified prior to module insertion.

Q: What is the mechanical function of the CHAS GND and C terminals on the terminal base? A: The CHAS GND terminal connects directly to the mounting DIN rail to establish a high-frequency noise grounding path for shielded encoder cabling, whereas the C terminal provides a direct return path for DC power.

Q: What operating voltage level does the 1734-VHSC5 inputs accept? A: The 1734-VHSC5 is specifically rated for 5 VDC differential or single-ended logic level encoder and counter inputs.

Field Installation Guidelines

• Secure the two-module assembly onto a standard 35 mm DIN rail, ensuring that the lower rail locking latch engages completely.
• Route shielded signal wires for high-speed counter inputs away from high-voltage AC cables. Terminate cable shields directly at the CHAS GND terminal on the base assembly.
• Verify that field wiring corresponds strictly to the 5 VDC operating signal level prior to energizing the system backplane.
• Tighten terminal block connection screws to specified manufacturer torque ratings (0.5 to 0.6 Nm) to maintain vibration resistance and electrical integrity.