Siemens SIMATIC PCS 7 Function Manual page 67

Once the read job has been executed, the communication block "FB_UA_RM" writes the
request data (including REQ_ID) and the pointer to the storage location data record to the
"UDT_UA_R_ST" input structure of the block, where it also sets the "NEW_DATA" input bit.
Note
For detailed information on the "UDT_UA_R_REQ_ST" and "UDT_UA_R_ST" structures, see
section Data structures and data formats (Page 241).
The input data are only assigned to the block's read job if the ID of the block (REQ_ID in the
output structure) matches the "REQ_ID" in the input structure.
Once the input structure data have been assigned to the read job, the data are checked for
validity and plausibility. The system evaluates the following:
● Whether the request data in the input and output structure match
● Whether the data length calculated corresponds to the data length of the outputs at the
block
If the data are plausible and valid, the "NEW_DATA" output is set and the data are written from
the "FB_UA_RM" communication block to the outputs of the block, where they are available
for further processing.
The "NEW_DATA" output is reset by resetting the "REC_REQ" request input.
The "FB_UA_RM" communication block reports any errors it detects during execution of the
read job to the "FB_STOR" block. The "FB_STOR" block deactivates the read job if an error
occurs ("REC_REQ" = 0). This also happens if the "FB_STOR" block itself detects an error.
A positive edge at the "RRESET" input resets the material data at the block output, the
"NEW_DATA" output and the error messages.
Writing data (updating actual values)
Following a request by a positive edge at request input "L_REC_W", the request data (REC_ID
(storage location ID), ARCH_NA /ARCH_NO, etc.) and the actual value input data are written
to the output structure "UDT_UA_W_REQ_ST". The write job is activated in the structure by
setting the "REC_REQ" bit.
Note
For detailed information on the "UDT_UA_W_REQ_ST" and "UDT_UA_W_ST" structures, see
section Data structures and data formats (Page 241).
Once the write job has been processed, the "FB_UA_WM" block writes the confirmation data
(including REQ_ID) to the "UDT_UA_W_ST" input structure of the block and sets the
"QWR_OK" bit.
The input data are only assigned to the block's write job if the ID of the block (REQ_ID in the
output structure) matches the "REQ_ID" of the input structure.
Once the input structure data have been assigned to the write job and the "QWR_OK" bit has
been set, the data are checked for validity and plausibility. The system checks whether the
request data in the input and output structure match.
Advanced Process Functions (APF)
Function Manual, 07/2016, A5E38719883-AA
Storage location management
5.1 FB_STOR (FB_STORI, FB_STORR)
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