Block Versioning - Siemens SIMATIC PCS 7 System Manual

4.6

Block versioning

Objective
The sections below describe how the engineering tool, depending on the defined parameters
and attributes
● Generates function blocks with corresponding inputs/outputs.
● Generates the user archive with corresponding column names.
This means there may be inconsistencies when changing parameters and attributes if the
workflow is not followed correctly. In order to prevent this, the APFs include the version-
checking mechanisms described below.
Block version
On generating a block, the Engineering Tool issues a "Generation version" (starting with 1)
and writes it in the block (input/output GEN_AS) and additionally in the file FB_Numbers.ini.
When making changes using the Engineering Tool (e.g. changes to attributes) and
regenerating the block, the number of the generation version will increase. The file thus
includes the current generation version for all of the generated blocks. When downloading, the
file FP_Numbers.ini is transferred to the OS.
Checking by Read / Writemanager FB_UA_RM / FB_UA_WM
If a block transmits a block to FB_UA_RM / FB_UA_WM, it also writes its generation version
(GEN_AS) in the telegram.
The scripts called by FB_UA_RM / FB_UA_WM read the target generation version from the
FB_Numbers.ini file and compare it with the generation version from the read/write requirement.
If the versions are not the same, the read-write jobs will not be executed. FB_UA_RM /
FB_UA_WM returns the target generation version to the requesting block.
Check at the requesting block
Using the function FB_CHECK , the requesting block compares its own version GEN_AS with
the returned version. In the case of an error, the error output QERR_VER is set and a message
is generated.
The block itself is not blocked.
The error output will be reset if a request is able to be successfully executed. The output
QRELEASED of the requesting bloick is statically set to TRUE and will be switched invisibly for
the CFC. The output QGR_ERR contains QERR_VER, but for reasons of compatibility only one
extended edge will be linked in by QERR_VER .
Note
This change in behavior of the blocks compared to previous APF versions may have
repurcussions on wired user blocks to QRELEASED and QERR_VER.
Advanced Process Functions Engineering Manual
System Manual, 07/2016, A5E38719921-AA
APF Engineering Tool
4.6 Block versioning
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