Technical data

The Master Mode – Commands, Sequence, Programming
4-5
SIMATIC NET AS-Interface – Introduction and Basic Information
C79000-G8976-C089/03
4.2 Data Transfer
Information/Data Structure
Before introducing you to the operating phases and the functions during these
operating phases, a brief outline of the information structure of the AS-i
master/slave system is necessary.
In the following diagram, the data fields and lists of the system are configured in
the system structure diagram you saw in the previous section.
PLC / PC
AS-i
slave
CPU
I/O data
Parameters
Configuration data
Act. params.
Act. configuration
data
LDS
LAS
Data images
Config. data
(EEPROM)
Parameters
LPS
Exp. configuration
data
I/O data
Address
User
program
AS-i master CP
Figure 4-2
The following structures are found on the AS-i master:
S Data images
These contain temporarily stored information:
– Actual parameters
The actual parameters are an image of the parameters currently on the AS-i
slave.
– Actual configuration data
The actual configuration data field contains the I/O configurations and ID
codes of all connected AS-i slaves once these data have been read from the
AS-i slaves.
– The list of detected AS-i slaves (LDS)
The LDS specifies which AS-i slaves were detected on the AS-i bus.