Siemens SIMATIC Distributed I/O System DP/ASi Link, Manual

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4-11
Distributed I/O System DP/ASi Link
EWA 4NEB 710 6055-02b
4.3.1 Selecting the Station Number for PROFIBUS-DP
With the station number, you identify every station of the PROFIBUS-DP.
The station number represents the name used by the DP master to address
individual stations.
With switch 8 of the DIP switch block (refer to Fig. 4-3), you define whether
the station number in the EEPROM or the station number on the DIP switch
block is valid.
Table 4-4 Station number selection on DIP switch block
Switch 8 Meaning Refer to
OFF Station number on DIP switch block is
valid. The station number in the EEPROM
is reset to station number 126 Section 4.3.2
ON Station number in the EEPROM is valid Section 4.3.3
You can set the station number within the range between 0 and 125. Station
numbers 126 and 127 are not authorized.
Address 126 is used to identify new DP slaves. Address 127 is reserved for
sending messages to a group of stations (multicasting, a sub-form of broad-
casting).
Note that you cannot use station numbers 124 and 125 with IM 308-C.
IM 308-C does not support diagnostics for these two station numbers.
If you use the station number stored in the EEPROM, you can modify it dur-
ing operation, as described in section 4.3.3.
You cannot modify the station number set with the DIP switch block during
operation. If you alter the station number on the DIP switch block, the new
station number is only taken into account after a cold restart.
Definition
Selecting station
numbers
Range of values
Modifying station
numbers
Installing and Wiring the DP/ASi Link