Allen-Bradley 1785-V40V VMEbus Programmable Controllers

The Allen-Bradley 1785-V40V brings reliable PLC-5 control capabilities to the standardized VMEbus architecture. Unlike standard rack-mounted controllers, this module operates within a “Versa Module Europa” chassis. It adheres strictly to ANSI/IEEE 1014-1987 communication standards for industrial computer components. This integration allows computer-based systems to execute programmable logic functions directly on the backplane. Consequently, users benefit from high-speed data exchange between the PLC and other VME-based specialized modules.

Master and Slave Communication Versatility

Flexibility in network roles defines the primary operational advantage of the 1785-V40V processor. The card functions effectively as either a bus master or a subordinate slave unit. As a master, the processor initiates data requests and manages other modules on the VMEbus. Conversely, slave mode allows external host computers to access the processor’s internal data tables. The module supports a massive capacity of 1,920 discrete I/O points and 1,920 analog I/O points. This dual-role capability makes it a powerful choice for complex, multi-processor industrial environments.

Memory Configuration and Network Ports

Engineers equipped the 1785-V40V with 48K words of high-speed SRAM for program and data storage. Connectivity options include four dedicated channels for Data Highway Plus (DH+) or Remote I/O. Additionally, a single RS-232C port provides a local interface for programming and serial device communication. The hardware design allows for high-density configurations within a standard 6U VMEbus chassis. Up to eight of these processors can reside in a single chassis simultaneously. This scalability supports massive parallel processing tasks for advanced automation requirements.

Technical Specifications