Siemens SIMATIC ET 200SP Manual page 180

Glossary
Slave profile
The slave profile classifies the basic properties of an AS-i slave. The slave profile consists of
the IO code, ID code, and ID2 code, which are stored as fixed, uneditable codes in each
slave. In addition, a slave has an ID1 code, which is saved in the slave as a fixed code or a
code that is editable by the user (e.g., with an addressing device). The value of the ID1 code
usually has no effect on the operating characteristics of the slave. In this case, the user
should not change the value, so that compatibility problems do not occur if the device is
replaced. Note the documentation of the slave for the ID1 setting.
Each of the four identification codes consists of a 4-bit value that is usually written in
hexadecimal notation with a value range of 0 to F. On power-up, the AS-i master reads the
codes automatically from each slave and saves this ACTUAL configuration in the volatile
memory of the AS-i master.
If the AS-i master is in "protected operation", it compares the ACTUAL configuration with a
CONFIGURED configuration, which is normally stored in non-volatile memory in the
AS-i master. Slaves whose ACTUAL configuration matches the CONFIGURED configuration
are activated and then participate in the cyclic data exchange. Slaves without a match are
not activated and do not exchange cyclic data. A configuration error is also signaled.
ID2 and ID1 are optional codes. That is, some slaves do not have these two codes. In this
case, the master enters the hexadecimal value "F" as a substitute value in the ACTUAL
configuration.
Slaves with extended addressing, the so-called A/B slaves, use only the three less
significant bits of the ID1 code as the slave identification. The most significant bit of the ID1
code is reserved and is used by the AS-i system to distinguish between an A address or B
address. The effective value range of the ID1 code is thus 0 ... 7. For the read-out of the ID
code, only the 3 less significant bits or all 4 bits are displayed, depending on the system, so
that the displayed ID1 code can be within the value range 8 to F for slaves with B address.
The user or programmer can ignore the most significant bit of the ID1 code for A/B slaves
since it is managed automatically by the system.
The slave profile is usually shown in the documentation with the S prefix and a hyphen (in
some cases), followed by the IO, ID, and ID2 codes, each separated by a dot.
Example: S-7.0.F
Since the ID1 code is usually editable, the value is often not documented or documented
only as a default value.
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AS-Interface master CM AS-i Master ST (3RK7137-6SA00-0BC1)
Manual, 07/2017, A5E02655262020A/RS-AD/004