Product Overview

The Allen-Bradley 1785-V80B is a high-performance VMEbus-based processor card that integrates the powerful logic capabilities of the PLC-5/40 enhanced controller into a VME chassis environment. Designed to comply with the Revision C.1 VMEbus specification, this module allows for high-speed, direct data exchange between a PLC-5 logic engine and other VME-based CPU modules or peripherals. It is specifically engineered for complex applications requiring the determinism of a PLC combined with the open-architecture flexibility of a VME system.

By residing directly on the VME backplane, the 1785-V80B eliminates the latency associated with traditional network bridges. It features a specialized VME status file that provides real-time monitoring of bus data and utilizes extended Ladder Diagram (LD) Message (MSG) instructions to facilitate seamless background data transfers and interrupt handling across the VMEbus.

Control Capacity and Communication Architecture

The 1785-V80B provides an expansive memory and I/O map, making it suitable for large-scale industrial deployments that involve high-density analog and digital processing.

• Massive Memory Footprint: Features a 100,000-word user memory capacity, supporting data table files up to 32,000 words each for extensive recipe storage or data logging.

• Versatile I/O Management: Capable of controlling up to 2,944 I/O points across 23 remote I/O racks and 92 remote chassis, ensuring full coverage for plant-wide automation.

• High-Speed Execution: Delivers a rapid scan time of 0.5 ms per 1,000 words of bit logic, maintaining high system responsiveness in dynamic environments.

• Flexible Port Configuration: Equipped with four configurable ports that can be assigned for Data Highway Plus (DH+) or Universal Remote I/O (RIO) messaging, along with a dedicated RS-232 serial port for local programming or modem connections.

Technical Specifications

• Manufacturer: Allen-Bradley (Rockwell Automation)

• Model Number: 1785-V80B

• Module Type: VMEbus Processor Card

• Platform Compatibility: PLC-5 Enhanced Series

• VME Specification: Revision C.1 Compliant

• Max. I/O Capacity: 2,944 Points (Any mix of Analog or Digital)

• Scan Time: 0.5 ms (Bit Logic); 2 ms (Typical) per 1k words

• Baud Rates: 57.6 kbps, 115.2 kbps, and 230.4 kbps

• User Memory: 100,000 Words

• Communication Ports: 4 Configurable (DH+/RIO) and 1 RS-232C

• Weight: 0.7 kg (1.54 lbs)

• Dimensions: 4.1 x 18.8 x 26.2 cm

Programming and System Integration

• Standard Logic Support: Executes standard PLC-5 ladder logic, allowing for easy migration of existing programs from standalone PLC-5/40 hardware.

• Direct VME Programming: The module can be programmed via the DH+ network, the local serial port, or directly through the VMEbus backplane from a co-resident host computer.

• Diagnostic Transparency: The integrated VME status file provides engineers with deep visibility into bus traffic, error codes, and synchronization status.

• Reliability: Designed for high-availability systems, this processor card provides a stable control layer for aerospace, defense, and high-speed scientific applications.