Siemens SIMATIC FM 353, Manual

Page: 93 / 361

Programming the Technological Functions
6-13
FM 353 Stepper Drive Positioning Module
6ES7 353-1AH01-8BG0
Parameters
The Table below lists the parameters for this block.
Name Data
Type
Param.
Type
Description
DB_NO INT I Data block number
RET_VAL INT Q Return value
Parameter types: I = input parameter, Q = output parameter
Return values
The function returns the following values:
RET_VAL BR Description
1 1 At least 1 job/transfer in progress
0 1 No job/transfer in progress, no error
< 0 0 Error:
S
Data error (AW-DB, DBX22.4)
S
Communication error (AW-DB, DBW66)
Function description
The function works together with an AW-DB user data block. The DB number is
passed to the function in the DB_NO parameter when the block is called.
S Start-up
POS_CTRL acknowledges start-up of the module. During this time, the
“RET_VAL” parameter and the “Write/Read job in progress” signals (AW-DB,
DBX68.0 and DBX68.2) are TRUE.
S Control and checkback signals
When POS_CTRL is called, the checkback signals are read from the FM 353
immediately (via direct access). Since the control signals and job requests are
processed after these signals have been read, the checkback signals reflect the
status of the module before the block was called. The control signals are also
written to the FM 353 using direct access.
Depending on the chosen mode, the control signals “Start, “Negative direction”
and “Positive direction” (AW-DB, DBX15.0, 15.2 and 15.3) are reset once
start-up has actually taken place (edge formation of the signals for the FM).
For information on the generation of the checkback signals “Process” (AW-DB,
DBX13.6) and “Position” (AW-DB, DBX13.7), see “Mode control”.