Siemens SIMATIC S7-1200

Communication
11.4 AS-i
S7-1200 Programmable controller
System Manual, V4.2, 09/2016, A5E02486680-AK
981
11.4.2
Exchanging data between the user program and AS-i slaves
11.4.2.1
STEP 7 basic configuration
The AS-i master reserves a 62-byte data area in the I/O area of the CPU. Access to the
digital data is performed here in bytes; for each slave, there is one byte of input and one byte
of output data.
The assignment of the AS-i connections of the AS-i digital slaves to the data bits of the
assigned byte is indicated in the inspection window of the AS-i master CM 1243-2.
You can access the data of the AS-i slaves in the user program by using the displayed I/O
addresses with the appropriate bit logic operations (for example, "AND") or bit assignments.
Note
"System assignment" is automatically activated if you do not configure the AS
-i slaves with
STEP
7.
If you do not configure any sl
aves, you must inform the AS-i master CM1243-2 about the
actual bus configuration using the online function "ACTUAL > EXPECTED".
Further information
You can find detailed information on the AS-i master CM 1243-2 in the "AS-i master CM
1243-2 and AS-i data decoupling unit DCM 1271 for SIMATIC S7-1200" Manual
(https://support.industry.siemens.com/cs/ww/en/ps/15750/man).