Technical data

Table Of Contents
Copy and Block Functions
System Software for S7-300/400 System and Standard Functions - Volume 1/2
3-20
A5E00709327-01
Working method
The SFC 83 "READ_DBL" is an asynchronous operating SFC, that is, processing
covers multiple SFC calls. Start the job by calling SFC 83 with REQ = 1.
The job status is displayed via the output parameters RET_VAL and BUSY.
See also Meaning of the Parameters REQ, RET_VAL and BUSY with
Asynchronous SFCs
Parameter Declaration Data type Memory
area
Description
REQ INPUT BOOL I, Q, M, D, L REQ = 1: Read request
SRCBLK INPUT ANY D Pointer to data block in the load memory that is
to be read from
RET_VAL OUTPUT INT I, Q, M, D, L Error information
BUSY OUTPUT BOOL I, Q, M, D, L BUSY = 1: The read process is not yet
terminated.
DSTBLK OUTPUT ANY D Pointer to the data block in the work memory
that is to be written to
Error Information
Error code
(W#16#...):
Description
0000 No error
8081 The source range is larger than the target range.
The target range is fully written. The remaining bytes of the source area are
ignored.
7000 First call with REQ=0: no data transfer active; BUSY has the value 0.
7001 First call with REQ=1: no data transfer active; BUSY has the value 1.
7002 Intermediate call (REQ irrelevant): data transfer already active; BUSY has the
value 1.
0081 The target range is larger than the source range.
The source area is written completely to the target area. The remaining
bytes of the target area are not changed.
80C0 The target is currently being processed by another SFC or communication
operation.
8093 No data block or a data block that is not in the work memory is indicated for the
parameter DSTBLK.
80B1 No data block is indicated for the parameter SRCBLK, or the data block indicated
there is not an object in the load memory (e.g. a DB generated by SFC 22).
80B4 DB with an F-attribute must not be read.
80C0 The destination DB is currently being processed by another SFC or a
communication function.
80C3 The maximum number of simultaneously active SFC 83 is currently reached.
8xyy
General error codes, see Evaluating Errors with Output Parameter RET_VAL