Advanet Advme1525

Introduction

The Advme1525 is a VME bus expander slave board which can be used in combination with the Advme1524 board (master board) to expand the number of VME bus slots.

The board bridges the read/write cycle and interrupt acknowledge cycle of the VME bus on the master side to the VME bus on the slave side. It has a bus arbiter function and bus master function, so there is no need for a CPU board or similar component on the slave side. The board supports bus cycles for 16-bit data buses and 24-bit address buses, and is ideal when you want to expand the number of slots in a system that uses a large number of DI, DO, AI, AO and other I/O boards

The board can be used to expand the number of VME bus slots. Daisy-chain connections are possible, allowing I/O boards to be distributed to multiple VME racks. Daisy-chain connections allow overall cable length to be extended
to 30m, and up to 16 slave boards can be connected to one master board. Inserting an I/O board with an interrupter function into the slot on the slave side enables the execution of an interrupt process with the CPU board on the master side. A setting can be specified so that only interrupt requests of a certain level are sent to the master board.

VME Bus Expander Configuration Example

The VME bus expander can control I/O boards and memory boards distributed to multiple racks with one CPU board. The configuration below is achieved by using a twisted flat cable to connect a master board (Advme1524) installed in the same rack as the CPU board with a slave board (Advme1525) installed on another rack. This master/ slave configuration allows direct access from the CPU board to I/O boards and memory boards in other racks.