Siemens SIMATIC S7-400 Reference Manual page 62

Structure of a CPU 41x
Sample Program
The small sample program below illustrates data transfer between the DP master
and DP slave. This example contains the addresses from Table 1-10.
In the DP Slave CPU
L 2
T MB 6
L EB 0
T MB 7
L MW 6
T PQW 310
CALL SFC 14
LADDR:=W#16#D
RET_VAL:=MW 20
RECORD:=P#M30.0 Byte20
L MB 30
L MB 7
+ I
T MW 100
Data Transfer in STOP Mode
The DP slave CPU goes into STOP mode: The data in the intermediate memory of
the CPU are overwritten with "0". In other words, the DP master reads "0".
The DP master goes into STOP mode: The current data in the intermediate
memory of the CPU are retained and can continue to be read by the CPU.
PROFIBUS Address
You cannot set 126 as PROFIBUS address for the CPU 41x as DP slave.
1-50
Preprocess data
in the DP slave
Transfer data to
the DP master
L
T
L
L
+
T
L
+
T
CALL
LADDR:= W#16#0
RECORD:= P#M60.0 Byte20
RET_VAL:= MW 22
Receive data
from the DP
master
Continue to
process received
data
In the DP Master CPU
PIB 222 Continue to
MB 50 process received
PIB 223 data in the DP
B#16#3 master
I
MB 51
10 Preprocess data
3 in the DP master
MB 60
SFC 15 Send data to the
DP slave
Automation System S7-400 CPU Specifications
A5E00165965-01