103BCommunication
10.4 AS-i
S7-1200 Programmable controller
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System Manual, 11/2011, A5E02486680-05
Bits 0 to 3 are used for user data.
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" must be activated if you do not configure the AS-i slaves with STEP 7.
If you do not configure any slaves, you must inform the AS-i master about the actual bus
configuration using the online function "ACTUAL > EXPECTED" of the TIA Portal.
Further information
You will find detailed information on the AS-i CM 1243-2 in the "CM 1243-2 and AS-i data
decoupling unit DCM 1271 for SIMATIC S7-1200" Manual.
10.4.3
Distributed I/O Instructions
The following Distributed I/O instructions (Page 260) can be used as indicated with AS-i:
●
RDREC instruction (Page 260): You can read a data record with the number INDEX from
an AS-i component.
●
WRREC instruction (Page 260): You can transfer a data record with the number INDEX
to an AS-i component defined by ID.
10.4.4
Working with AS-i online tools
Changing AS-i operational modes online
You must go online to view and change the AS-i operational modes.
In order to go online, your must first be in "Device configuration" with the CM1243-2 AS-i
Master module selected, and then click the "Go online" button in the toolbar. Next, select the
"Online and diagnostics" command from the "Online" menu.