Monitoring and regular control of network
components allow us to get a complete overview of the status and
availability of an industrial network. It is important to be able
to monitor and, if necessary, change the factors that influence
them. In this entry, the following requirements are to be met:
- Providing also S7 CPUs with an option to control the network
- Controlling the digital I/O of a new SCALANCE W748-1 RJ45 IWLAN
component using network management functions. This function can be
used to deliberately switch off specific plant sections of, for
example, monorail conveyors.
Network management systems monitor and, if necessary, control the
status of SNMP-capable network components via SNMP (Simple Network
Management Protocol). The blocks of the "SNMP_Library" and the
applications now allow you to use a SIMATIC S7 CPU with PROFINET
interface to poll all desired information from network components
and, if necessary, control them.
The diagram below shows a network where the S7 CPU controls
different network components.
In the download area, three documents are available that deal
with the topic of this entry.
SNMP library for STEP 7 5.5
- The library contains all necessary blocks for reading and
writing SNMP variables for S7 CPUs with integrated PROFINET
Simple application example of the SNMP library
- The application example shows you how to use the blocks of the
SNMP library in order to read and write different SNMP variables
from SCALANCE switches from the S7 CPU.
- The example was created in FBD.
SNMP control block for control and status check of the
digital IO of a SCALANCE W748-1 IWLAN client
- This application example shows the programming of a block that
can read and switch the digital output of a SCALANCE W748-1 RJ45
with the aid of the SNMP library.
- The user block was created in SCL.
Note on security
The functions and solutions described in this entry
predominantly confine themselves to the realization of the
automation task. Please also take into account that corresponding
protective measures have to be taken in the context of Industrial
Security when connecting your equipment to other parts of the
plant, the enterprise network or the Internet. For more
information, please refer to Entry ID 50203404.
The Library blocks SNMP_GET (FB 100)
and SNMP_SET (FB 101) have been changed.