BECKHOFF BK5200 - Manual (Page 17)

Basic Principles
BK52x0 17
Four groups are distinguished in the assignment:
Functional type of the channel Assignment level
1. Analog outputs assignment by bytes
2. Digital outputs assignment by bits
3. Analog inputs assignment by bytes
4 Digital inputs assignment by bits
Complex multi-byte signal Bus Terminals are represented as analog inputs
or outputs.
The distribution of the process image in the Bus Coupler in overview:
Output data in the Bus
Coupler
O0
...
byte-oriented data
...
Ox
Ox+1
bit-oriented data
Ox+y
Input data in the Bus
Coupler
I0
...
byte-oriented data
...
Ix
Ix+1
...
bit-oriented data
...
Ix+y
The path from the I/Os to
the DeviceNet process
image
Data consistency Data whose content is all correctly associated is said to be consistent.
Examples of data items that belong together are: 1. the high and low bytes
of an analog value (word consistency), and 2. a control/status byte and the
associated parameter word for access to the registers. Data consistency in