Interface, User Data Blocks (Aw-Dbs) - Siemens SIMATIC FM 353 Manual

Programming the Technological Functions
Function description
The function works together with an AW-DB user data block. When the function is
called, the DB number is forwarded in the DB_NO parameter.
Reading of the measured value is started by setting the IN_MSR parameter to
TRUE. When the function has executed, the block resets the parameter.
The IN_MSR parameter remains set while the function is executing. Transfer of the
data is terminated is complete when the parameter is reset (IN_MSR = FALSE).
Error evaluation
Errors are flagged in the Binary Result (BR = 0) and by RET_VAL < 0.
Possible errors are as follows:
Data transfer errors during transfers with SFC 59 "RD_REC". The error is made
available in the user data block AW-DB, DBW98 (see Error List, Section 6.8).
6.3.6

Interface, user data blocks (AW-DBs)

The AW-DB (interface) is created off-line.
The user can access the signals and/or data on the interface using absolute or
symbolic addresses (creation of the AW-DB with UDT structure).
The interface is allocated to the relevant channel/axis via the standard function
blocks' DB_NO input parameter. The module address is part of the user DB. It is
entered either by the POS_INIT block or manually via "Parameterize FM 353" (but-
ton "Enter Mod-Adr in user DB" in main display). The user DB must already exist.
6-26
FM 353 Stepper Drive Positioning Module
6ES7 353-1AH01-8BG0