Technical data

Copy and Block Functions
System Software for S7-300/400 System and Standard Functions - Volume 1/2
A5E00709327-01
3-7
Exceptions
The following cannot be used as the source field:
• Counters
• Timers
You cannot write values to the following using SFC 21:
• The following block types: FB, SFB, FC, SFC, SDB,
• Counters,
• Timers,
• Memory areas of the peripheral I/O area.
Parameter Declaration Data Type Memory Area Description
BVAL INPUT ANY I, Q, M, D, L The parameter BVAL contains the value or
description of the area whose contents will
be
used to initialize the destination area (source
area). Arrays of the data type STRING are
not permitted.
RET_VAL OUTPUT INT I, Q, M, D, L If an error occurs while the function is being
processed, the return value contains an error
code.
BLK OUTPUT ANY I, Q, M, D, L The parameter BLK contains the description
of the area to be initialized (destination area).
Arrays of the data type STRING are not
permitted.
The Input Parameter is a Structure
If you transfer a structure as the input parameter, remember the following point:
STEP 7 always defines the length of a structure as an even number of bytes. As a
result, the structure will need one byte of additional memory space if you declare a
structure with an odd number of bytes.
Example
The structure was declared as:
TYP_5_BYTE_STRUCTURE : STRUCT
BYTE_1_2 : WORD
BYTE_3_4 : WORD
BYTE_5 : BYTE
END_STRUCT
The declared structure "TYP_5_BYTE_STRUCTURE" requires 6 bytes of memory.
Error Information
SFC 21 "FILL" only provides general (not specific) error information. See
Evaluating Errors with Output Parameter RET_VAL.