7
Deployment PROFIBUS communication
7.1 Overview
n
PROFIBUS is an international standard applicable to an open and serial field bus for
building, manufacturing and process automation that can be used to create a low
(sensor-/actuator level) or medium (process level) performance network of program-
mable logic controllers.
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PROFIBUS comprises an assortment of compatible versions. The following details
refer to PROFIBUS DP.
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PROFIBUS DP is a special protocol intended mainly for automation tasks in a manu-
facturing environment. DP is very fast, offers Plug'n'Play facilities and provides a cost-
effective alternative to parallel cabling between PLC and remote I/O. PROFIBUS DP
was designed for high-speed data communication on the sensor-actuator level.
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The data transfer referred to as "Data Exchange" is cyclical. During one bus cycle,
the master reads input values from the slaves and writes output information to the
slaves.
The PROFIBUS DP master is to be configured in the hardware configurator from Sie-
mens. Therefore the configuration happens by the sub module X1 (MPI/DP) of the Sie-
mens CPU.
After the transmission of the data to the CPU, the configuration data are internally passed
on to the PROFIBUS master part.
During the start-up the DP master automatically includes his data areas into the address
range of the CPU. Project engineering in the CPU is not required.
Via the PROFIBUS DP master PROFIBUS DP slaves may be coupled to the CPU. The
DP master communicates with the DP slaves and links up its data areas with the address
area of the CPU.
At every POWER ON res. overall reset the CPU fetches the I/O mapping data from the
master. At DP slave failure, the ER-LED is on and the OB 86 is requested. If this is not
available, the CPU switches to STOP and BASP is set. As soon as the BASP signal
comes from the CPU, the DP master is setting the outputs of the connected periphery to
zero. The DP master remains in the operating mode RUN independent from the CPU.
For the deployment in a super-ordinated master system you first have to project your
slave system as Siemens CPU in slave operation mode with configured in-/output areas.
Afterwards you configure your master system. Couple your slave system to your master
system by dragging the CPU 31x from the hardware catalog at
Configured stations
onto
the master system, choose your slave system and connect it.
PROFIBUS DP
CPU with DP master
Deployment of the DP
master with CPU
DP slave operation
System 300S
+
Deployment PROFIBUS communication
Overview
HB140 | CPU | 315-4PN23 | en | 18-02
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