Packed Addressing Table; Special Feature Of As-I Analog Slaves; Points To Note About As-I Safety Slaves; Accessing As-I Digital Data - Siemens SIMATIC NET DP/AS-i Link 20E Manual

Data exchange between DP master and AS-i slave
2.3.4

Packed addressing table

The "Pack" function in the properties dialog of the AS-i line is used to optimize the
use of addresses, in other words, all gaps are eliminated (see Section 1.10.3).
You can take the addresses of the binary data directly from the configuration.
2.3.5

Special feature of AS-i analog slaves

If you use slaves complying with CTT 1-5, then depending on the slave, all or
some I/O bits may be used for special transfer functions.
The following applies to these protocol bits:
S In the input direction, the DP/AS–i LINK sets the value "0";
S In the output direction, the DP/AS–i LINK ignores the bits;
How to access AS-i analog slaves is described in Section 2.4.
2.3.6

Points to note about AS-i safety slaves

The DP/AS-i LINK sets the input bits
S 0 and 1 = 0 if the contact at F-IN1 is open;
S 0 and 1 = 1 if the contact at F-IN1 is closed;
S 2 and 3 = 0 if the contact at F-IN2 is open;
S 2 and 3 = 1 if the contact at F-IN2 is closed;
2.3.7

Accessing AS-i digital data

The DP master is the decisive factor
How you access binary data of the AS-i slaves depends on the DP master you are
using. Please refer to the relevant user documentation.
SIMATIC S7 is DP master
If you have configured the I/O addresses of the DP/AS-i Link 20E in the area of the
process image, you can access the AS-i binary values with single bit commands.
Example (see also Figure 2-2):
A I 1.0
= Q 1.3
50
//Connector 1 on AS-i module 3
//Connector 4 on AS-i module 3
DP/AS-Interface Link 20E
Release 08/2008
C79000-G8976-C235−01