BECKHOFF C1300 User Manual
Page 9
C1300 VME to II/O Interface Unit
Beckhoff II/O-System
Date : 18.12.95
Version : 2.01
Page 9 of 44
The Beckhoff II/O fieldbus consists of a physical ring, that can be split into 8 logical rings in
order to process the signal states. A logical ring can only be run on preselected modules,
which are defined by Communication Description Lists ( CDLs ) or freely programmable
comunications. Later in this text the way this definitions are transmitted will be delt with.
The host system is provided with the signal states via the DPRAM, which can be divided into
3 areas.
-Data :
Input , output
-Communications :
Initialization, test, analysis and configuration of the II/O-
Systems
-Process control :
Refresh of signal states
The central module needs an area of 4 Kbyte in the address space of the host system.