Operating Instructions
IS1 PROFIBUS 3.00 E
- Technical alterations reserved -
24
PROFIBUS DP interface for IS1+
Configuration of PROFIBUS master
Only one of two redundant CPUs is configured in the DP master with the primary DP address.
The application in PLC/DCS is using only the primary CPU for exchanging I/O data.
Consider that the backup address according parameter ´Address offset backup CPU PNO Red´
is allocated and shall not be used twice.
Cyclic or acyclic communication between DP master and the backup CPU may be optionally used for
checking the backup communication line.
The accepted ´Max. Slave switch over time´ from the DP master for bumpless switch over depends on
the setting of DP Watchdog time and the DP master cycle.
Rule for 9440 CPM:
Max. Slave switch over time [ms] = DP-Wa (3 * DP master cycle) + 470ms
DP master
cycle
[ms]
Max. Slave switch over time [ms]
Worst case time between disturbing DP
bus on primary CPU to Data_Exchange of
previous backup CPU.
Setting of Parameter
´ Timeout for output
modules´
>=
[s]
DP-Watchdog [ms]
50
100
200
500
1000
10
550
600
700
1000
1500
1,0
30
610
660
760
1060
1560
1,0
50
-
720
820
1120
1620
1,0
70
-
780
880
1180
1680
1,0
80
-
810
910
1210
1710
1,1
100
-
-
970
1270
1770
1,2
150
-
-
1120
1420
1920
1,4
200
-
-
-
1570
2070
1,6
Recommendation using Siemens PLCs with IS1+: use DP Master profile ´Universal (DP/FMS)´.