Technical data

Table Of Contents
SFCs/SFBs for Transferring Data Records
System Software for S7-300/400 System and Standard Functions - Volume 1/2
7-6
A5E00709327-01
7.4 Writing Dynamic Parameters with SFC 55 "WR_PARM"
Description
With SFC 55 "WR_PARM" (write parameter), you transfer the data record
RECORD to the addressed module. Parameters transferred to the module do not
overwrite parameters configured with STEP7.
Requirements
The data record to be transferred must not be static.
(Refer to /71/ and /101/ for more information on static data records.)
Parameter Declaration Data Type Memory Area Description
REQ INPUT BOOL I, Q, M, D, L,
constant
REQ = 1: Write request
IOID INPUT BYTE I, Q, M, D, L,
constant
ID of the address area:
B#16#54 =Peripheral input (PI)
B#16#55 =Peripheral output (PQ)
If the module is a mixed module, specify the
area ID of the lowest address. If the addresses
are the same, specify B#16#54.
LADDR INPUT WORD
I, Q, M, D, L,
constant
Logical base address of the module. With
mixed
modules, specify the lower of the two
addresses.
RECNUM INPUT BYTE I, Q, M, D, L,
constant
Data record number
RECORD INPUT ANY I, Q, M, D, L Data record
RET_VAL OUTPUT INT I, Q, M, D, L If an error occurs while the function is active,
the return value contains an error code.
BUSY OUTPUT BOOL I, Q, M, D, L BUSY = 1: Writing is not yet completed.
Input Parameter RECORD
The data to be transferred are read from the parameter RECORD during the first
SFC call. If the transfer of the data record takes longer than the duration of a call,
the contents of the parameter RECORD are no longer relevant for the subsequent
SFC calls (for the same job).
Error Information
Assigning Parameters to a Module with SFC 57 "PARM_MOD"
Note
(S7-400 only)
If the general error W#16#8544 occurs, this only indicates that access to at least
one byte of the I/O memory area containing the data record was denied. The data
transfer was continued.