Siemens SIMATIC S7 System Manual page 436

Communication
8.5 PROFIBUS
These SM locations show default values if DP communications have not been established
with a DP master. After a DP master has written parameters and I/O configuration to the
EM DP01 PROFIBUS DP module, these SM locations show the configuration set by the DP
master. You should check the protocol status byte (for example SMB1424 for slot 0) to be
sure that the EM DP01 is currently in data exchange mode with the DP master before using
the information in the SM locations shown in the following table or data in the V memory
buffer.
Note
You cannot configure the EM DP01 PROFIBUS DP I/O buffer sizes or buffer location by
writing to SM memory locations. Only the DP master can configure the EM DP01
PROFIBUS DP module for DP operation.
Table 8- 4
Intelligent
module in
SMB1400
SMB1401
SMW1402
SMB1404
SMB1405
SMB1406
SMB1407 to
SMB1449
Note: SM locations are updated each time the DP device accepts configuration / parameterization
information. These locations are updated even if a configuration/parameterization error is detected.
The locations are cleared on each power up.
Note: This information is also available in the STEP 7-Micro/WIN SMART "PLC information" for the
EM DP01.
Note: The user program can access this information and use it to process the EM DP01 data.
436
Special memory bytes for the EM DP01 PROFIBUS DP
... Intelligent
module in
slot 0 slot 5
... SMB1650
... SMB1651
... SMW1652
... SMB1654
... SMB1655
... SMB1656
... SMB1657 to
SMB1699
DP device's station address as set by address switches (0 - 99
decimal)
Address of the DP device's master (0 to 126) (displays 255 if no DP
master is attached)
V memory address of the output buffer as an offset from VB (for
example, 1000 means VB1000).
Number of bytes of output data
Number of bytes of input data
DP standard protocol status byte
Num-
ber
0 DP communications not initiated since power on
1 Configuration/parameterization error detected
2 Currently in data exchange mode
3 Dropped out of data exchange mode
Reserved - cleared on power up
System Manual, V2.3, 07/2017, A5E03822230-AF
Description
Description
S7-200 SMART