Siemens SIMATIC S7-1200

Communication processor and Modbus TCP
13.4 Universal serial interface (USS) communication
S7-1200 Programmable controller
System Manual, V4.2, 09/2016, A5E02486680-AK
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13.4.1
Selecting the version of the USS instructions
There are two versions of USS instructions available in STEP 7:
● Version 2.0 (legacy instructions) was initially available in STEP 7 Basic/Professional V13.
● Version 2.1 is available in STEP 7 Basic/Professional V13 SP1 or later.
For compatibility and ease of migration, you can choose which instruction version to insert
into your user program.
You cannot use both versions of the instructions with the same module, but two different
modules can use different versions of the instructions.
Click the icon on the instruction tree task card to enable the headers and columns
of the instruction tree.
To change the version of the USS instru
c-
tions, select the version from the drop
-down
list. You can select the group or individual
instructions.
When you use the instruction tree to place a USS instruction in your program, a new FB or
FC instance, depending on the USS instruction selected, is created in the project tree. You
can see new FB or FC instance in the project tree under PLC_x > Program blocks > System
blocks > Program resources.
To verify the version of a USS instruction in a program, you must inspect project tree
properties and not the properties of a box displayed in the program editor. Select a project
tree USS FB or FC instance, right-click, select "Properties", and select the "Information"
page to see the USS instruction version number.