Technical data

Table Of Contents
System Functions for Addressing Modules
System Software for S7-300/400 System and Standard Functions - Volume 1/2
A5E00709327-01
15-3
15.2 Querying the Module Slot Belonging to a Logical
Address with SFC 49 "LGC_GADR"
Description
With SFC 49 "LGC_GADR" (convert logical address to geographical address), you
obtain the module slot belonging to a logical address and the offset in the user data
address area of the module.
Note
SFC 49 "LGC_GADR" can not be used on submodule with packed addresses
(ET 200S).
Parameter Declaration Data Type Memory Area Description
IOID INPUT BYTE I, Q, M, D, L,
constant
ID of the address area:
B#16#00: Bit 15 of LADDR
specifies whether an input (Bit15=0)
or output address (Bit 15=1) exists.
B#16#54 = Peripheral input (PI)
B#16#55 = Peripheral output (PO)
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 address. With mixed modules,
specify the lower of the two addresses.
RET_VAL OUTPUT INT I, Q, M, D, L Error information
AREA OUTPUT BYTE I, Q, M, D, L Area ID: this specifies how the
remaining output parameters must be
interpreted.
RACK OUTPUT WORD I, Q, M, D, L Rack number
SLOT OUTPUT WORD I, Q, M, D, L Slot number
SUBADDR OUTPUT WORD I, Q, M, D, L Offset in the user data address area of
the corresponding module.
Note
If you are using an S7-400H PLC in fail-safe mode and specify the logical address
of a module in a connected DP slave when calling SFC 49 in the parameter
LADDR, the DP master system ID of the active channel will be supplied in the high
byte of the RACK parameter. If no active channel exists, the DP master system ID
for the associated DP master system is output to the master CPU.