Siemens SIMATIC PCS 7 Function Manual page 21

Area of application
The block executes the following functions:
● Writing one or more data records from an AS data block to an OS user archive on request
● Monitoring communication (generation of alarms)
Startup characteristics
The "FB_UA_WM" block is called from the startup OB upon CPU startup. This call is configured
during CFC configuration by the CFC editor. Internal data and outputs are reset upon startup.
Program execution starts once the "RUNUPCYC" cycles have elapsed.
During startup, the output "QRUN_UP" = 1.
Time characteristics
The block must be called from a cyclic interrupt OB.
Communication
Communication on the AS level between the requesting block and the FB_UA_WM block is
implemented with the "UDT_UA_W_REQ_ST" (request) and "UDT_UA_W_ST" (feedback)
structures.
The data is written through the "BSEND" block, which occurs twice in the "FB_UA_WM" block,
enabling the establishment of a redundant connection.
OS tags are used to coordinate the data communication between the AS and OS. Appropriate
scripts associated with the function block and its functionalities are triggered for operator
control at the OS level.
The "ALARM_8P" structure is used to implement data communication with the OS message
system.
Note
For information on configuring the "FB_UA_WM" block, refer to the APF Engineering Manual.
Advanced Process Functions (APF)
Function Manual, 07/2016, A5E38719883-AA
Communication
2.2 FB_UA_WM
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