Siemens Simatic S7-300, Hardware And Installation Manual, Page: 178 / 242

Testing functions, Diagnostics and Fault Elimination
S7-300 Programmable Controller Hardware and Installation
10-18
A5E00105492-01
STEP 7 User Program
STL Description
CALL SFC 59
REQ :=TRUE
IOID :=B#16#54
LADDR:= W#16#200
RECNUM :=B#16#1
RET_VAL :=MW2
BUSY :=MO.0
RECORD :=P# DB10.DBX 0.0 BYTE 240
//Request to read
//Identifier of the address area, here the I/O input
//Logical address of the module
//Data record 1 is to be read
//An error code is output if an error occurs
//Read operation not finished
//DB 10 is target area for the read data record 1
Note
data is only returned to the target area if BUSY is reset to 0 and if no negative
RET_VAL has occurred.
Diagnostic Addresses
With CPU 31x-2 you assign diagnostic addresses for the PROFIBUS-DP. Make
sure during configuration that DP diagnostic addresses are assigned to the DP
master and to the DP slave.
When you configure ithe DP
masters, you have to specify (in
the associated project of the
DP masters) a diagnostic
address for the DP slave. In the
following, this diagnostic address
is refered to as
.
The DP master recieves
information on the status of the
DP slaves or on a bus
interruption via this diagnostic
address.
allocated to the
DP master
When you configure the DP slaves
you must also specify (in the
associated projects of the DP
slaves) a diagnostic address that is
allocated to the DP slave. In the
following, the diagnostic address is
refered to
as allocated to the DP
slave.
The DP slave receives information
on the status of the DP masters or
on a bus interruption via this
diagnostic address.
CPU as DP master
CPU as DP slave
During configuration you must specify two diagnostic addresses:
PROFIBUS DP
Diagnostic address Diagnostic address