Technical data

Table Of Contents
SFCs/SFBs for Transferring Data Records
System Software for S7-300/400 System and Standard Functions - Volume 1/2
7-4
A5E00709327-01
7.2 Reading Defined Parameters with SFC 54
"RD_DPARM"
Description
With SFC 54 "RD_DPARM" (read defined parameter), you read the data record
with the number RECNUM of the addressed module from system data configured
with STEP 7. The data record that is read is entered in the destination area opened
by the parameter RECORD.
Parameter Declaration Data Type Memory Area Description
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 (permitted values: 0 to
240)
RET_VAL OUTPUT INT I, Q, M, D, L Length of the data record read in bytes if
the read data record fits in the destination
area
and no error occurred in the transfer.
If an error occurs while the function is active,
the return value contains an error code.
RECORD OUTPUT ANY I, Q, M, D, L Destination area for the read data record.
Only
the data type BYTE is permitted.
Error Information
Assigning Parameters to a Module with SFC 57 "PARM_MOD"