Technical data

The Master Mode – Commands, Sequence, Programming
4-3
SIMATIC NET AS-Interface – Introduction and Basic Information
C79000-G8976-C089/03
4.1.1 Tasks and Functions of the AS-i Master
Graded Range of Performance – Use of Profiles According to the AS-i
Specification
The AS-i master specification distinguishes masters with different ranges of
functions known as a “profile”.
For standard AS-i masters and extended AS-i masters there are three different
master classes (M0, M1, M2 for standard masters, M0e, M1e, M2e for extended
masters). The AS-i specification stipulates which functions a master in a particular
class must be able to perform (refer also to the PICS in the appendix of the manual
for the particular CP).
The profiles have the following practical significance:
S Master profile M0 / M0e:
The AS-i master can exchange I/O data with the individual AS-i slaves. The
master is configured by using the station configuration found on the cable
known as the “expected configuration”.
S Master profile M1 / M1e :
This profile covers all the functions according to the AS-i master specification.
S Master profile M2 / M2e:
The functionality of this profile corresponds to master profile M0/M0e, but in this
profile the AS-i master can also assign parameters to the AS-i slaves.
The essential difference between extended AS-i masters and standard AS-i
masters is that they support the attachment of up to 62 AS-i slaves using the
extended addressing mode. Extended AS-i masters from SIMATIC NET also
provide particularly simple access for AS-Interface analog slaves complying with
profile 7.3/7.4.
Note
If you decide to use standard operation (master profile M0), you can skip the
remaining sections in this chapter. Continue reading in the manual of your CP to
find out the steps required for installation and operating the module.