8 Deployment PROFIBUS communication
8.1 Overview
n PROFIBUS is an international standard applicable to an open and
serial field bus for building, manufacturing and process automa-
tion that can be used to create a low (sensor-/actuator level) or
medium (process level) performance network of programmable
logic controllers.
n PROFIBUS comprises an assortment of compatible versions. The
following details refer to PROFIBUS DP
.
n PROFIBUS DP is a special protocol intended mainly for automa-
tion tasks in a manufacturing 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.
n 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 con-
figurator from Siemens. Therefore the configuration happens by the
sub module X1 (MPI/DP) of the Siemens 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.
V
ia the PROFIBUS DP master PROFIBUS DP slaves may be cou-
pled 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 map-
ping 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 inde-
pendent 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 sta-
tions 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
VIPA System 300SDeployment PROFIBUS communication
Overview
HB140 | CPU | 314-6CF03 | GB | 16-43 194
To Next Page
Loading...
