Technical data

System Functions for Addressing Modules
System Software for S7-300/400 System and Standard Functions - Volume 1/2
15-6 A5E00709327-01
15.4 Determining the Start Address of a Module with SFC 70
"GEO_LOG"
Description
Assumption: the associated module slot of the module is known from the channel
of a signal module. With SFC 70 "GEO_LOG" (convert geographical address to
logical address) you can determine the associated start address of the module, that
is, the smallest I address or Q address.
Parameters
Parameter Declaration Data Type Memory Area Description
MASTER INPUT INT I, Q, M, D, L,
constant
Area ID:
• 0, if the slot is located in one of
the racks 0-3 (central unit)
• 1 to 31: DP master system ID of
the associated field device if the
slot is located in a field device on
PROFIBUS
• 100 to 115: PROFINET IO
system ID of the associated field
device if the slot is located in
afield device on PROFINET
STATION INPUT INT I, Q, M, D, L,
constant.
No. of rack, if
area ID= 0
Station number of field device if area
ID> 0
SLOT INPUT INT I, Q, M, D, L,
constant
Slot no.
SUBSLOT INPUT INT I, Q, M, D, L,
constant
Interface module slot (if no interface
module can be inserted, enter 0 here)
RET_VAL OUTPUT INT I, Q, M, D, L Error information
LADDR OUTPUT WORD I, Q, M, D, L Start address of the module
Bit 15 of LADDR indicates whether an
input address (bit 15 = 0) or an output
address (bit 15 = 1) is present