Siemens SIMATIC FM 353, Manual

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Programming the Technological Functions
6-42
FM 353 Stepper Drive Positioning Module
6ES7 353-1AH01-8BG0
Parameters
The Table below lists the parameters for the POS_MSRM block.
Name Data
type
Param.
type
Description
DB_NO INT I Data block number
RETVAL INT Q − 1
IN_MSR BOOL I/Q Start Read
Parameter types: I = input parameter, Q = output parameter,
I/Q = throughput parameter (initiation parameter)
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 RETVAL < 0.
Possible errors are as follows:
Data transfer errors during transfers with SFB 52 “RDREC”. The error is made
available in the user data block AW-DB, DBW98 (see Error List, Section 6.8).
6.4.6 Interface, user DBs (AW-DBs)
User DB 1 is the user data block in the default condition of the function blocks; it’s
symbolic name is IFFM_ICTRL. This DB consists of the user data interface and
the instance data of the POS_CTRL block (FB 1).
The user can access the signals and/or data on the interface using absolute or
symbolic addresses if reference is made via the symbol table of the project.
When calling POS_CTRL, the interface is transferred as an instance. With the
other standard function blocks, the interface is assigned to the appropriate
channel/axis using the DB_NO input parameter.