Elements Of Asi - Siemens SIMATIC Distributed I/O System DP/ASi Link Manual

2.2

Elements of ASi

DP/ASi link
The DP/ASi link is the ASi master. It controls communication in the ASi.
The DP/ASi link periodically exchanges data with the ASi slaves.
ASi slave ASi slaves are the input and output channels of the ASi. ASi slaves transfer
data to the DP/ASi link when requested to do so by the DP/ASi link. ASi
slaves are:
You differentiate between the individual ASi slaves by means of an ASi ad-
dress that you can set. You set the ASi address, for example, by using the ASi
addressing unit (Order No: 3RX9 400-0AA00).
All ASi slaves are supplied ex works with an ASi address of 0. This ASi ad-
dress is not enabled within the ASi for data exchange.
I/O code
The I/O code contains the definition of the distribution of the inputs and out-
puts of the different ASi slaves. You will find the complete I/O code in Ap-
pendix B.
You choose the ASi slave type according to the distribution of inputs and
outputs. From the viewpoint of the DP/ASi link, sensors are inputs and actua-
tors are outputs.
ID code
The ID code is an additional code that be optionally used for any ASi slave.
The ID code is specified for every ASi slave. The default value for the ID
code is 0.
Distributed I/O System DP/ASi Link
EWA 4NEB 710 6055-02b
Modules
You connect up to 4 binary actuators and sensors to a single module.
A supply voltage of 24 VDC is available for the actuators and sensors at
the output of the modules.
You can combine different upper and lower parts to form a module, de-
pending on the application. The configuration of a module depends on
the:
– ASi cable used
– number of inputs and outputs (I/O code)
– use of an external power supply unit
You will find an example of a module in section 2.3.
Intelligent actuators or sensors
You connect intelligent actuators and sensors directly to the ASi cable.
ASi Basics
2-3