PROFIBUS DP syncOut
The DP master system is waiting
for CPU output data.
PROFIBUS DP syncInOut
CPU and DP master system are
waiting on each other and form
thereby a cycle.
Default: PROFIBUS DP async
5.9.2.1.1 Synchronization between master system and CPU
Normally the cycles of CPU and DP master run independently. The
cycle time of the CPU is the time needed for one OB1 cycle and for
reading respectively writing the inputs respectively outputs. The cycle
time of a DP master depends among others on the number of con-
nected slaves and the baud rate, thus every plugged DP master has
its own cycle time. Due to the asynchronism of CPU and DP master
the whole system gets relatively high response times. The synchroni-
zation behavior between every VIPA PROFIBUS DP master and the
CPU may be configured by means of a hardware configuration as
shown above. The different modes for the synchronization are in the
following described.
In PROFIBUS DP SyncInOut mode CPU and DP master system are
waiting on each other and form thereby a cycle. Here the whole cycle
is the sum of the longest DP master cycle and CPU cycle. By this
synchronization mode you receive global consistent in-/ output data,
since within the total cycle the same input and output data are han-
dled successively by CPU and DP master system. If necessary the
time of the Watchdog of the bus parameters should be increased at
this mode.
In this operating mode the cycle time of the VIPA DP master system
depends on the CPU cycle time. After CPU start-up the DP master
gets synchronized. As soon as their cycle is passed they wait for the
next synchronization impulse with output data of the CPU. So the
response time of your system can be improved because output data
were directly transmitted to the DP master system. If necessary the
time of the Watchdog of the bus parameters should be increased at
this mode.
Overview
PROFIBUS DP
SyncInOut
PROFIBUS DP SyncOut
VIPA System 300S CPU
Deployment CPU 315-2AG13
Setting VIPA specific CPU parameters > VIPA specific parameters
HB140 | CPU | 315-2AG13 | GB | Rev. 14-40
51