Siemens SIMATIC ET 200AL, System Manual

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Diagnostics and maintenance
4.7 Diagnostics of the network topology
PROFINET with STEP 7
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Function Manual, 05/2021, A5E03444486-AL
4.7 Diagnostics of the network topology
Availability
As an open standard, you can use any SNMP based systems or software solutions for
diagnostics in PROFINET.
Network diagnostics
The network management protocol SNMP (Simple Network Management Protocol) uses the
wireless UDP transport protocol. It consists of two network components, similar to the
client/server model. The SNMP manager monitors the network nodes and the SNMP clients
collect the various network-specific information in the individual network nodes and store it
in a structured form in the MIB (Management Information Base). This information allows a
network management system to run detailed network diagnostics.
MIB
The MIB (Management Information Base) is the database of a device. SNMP clients access this
database in the device. The S7 device family supports the following standard MIBs:
•
MIB II, standardized in the RFC 1213
• LLDP-MIB, standardized in the international standard IEC 802.1AB
• LLDP-PNIO-MIB, standardized in the international standard IEC 61158-6-10
You will find the MIBs for ET 200 interface modules and couplers with PROFINET interface in
this product note ( https://support.industry.siemens.com/cs/ww/en/view/109770525 ).
Detecting the network topology
LLDP (Link Layer Discovery Protocol) is a protocol that is used to detect the closest neighbor.
LLDP enables a device to send information about itself and to receive information from its
neighbor devices. This information is then saved in the LLDP MIB, for example, and can be
queried using SNMP. This information allows a network management system to determine
the network topology.
Use of SNMP (Simple Network Management Protocol)
SNMP can be used as follows:
•
By users to integrate network diagnostics into a central HMI/SCADA system using the
SIMATIC NET OPC server
• By the IT administration of machine and plant operators to monitor their Industrial
Ethernet network using standard network management systems.
• By the IT administration, to monitor the automation network, alongside the office
network, using standard network management systems.
Use of SNMP in the SIMATIC NET environment
SNMP-compliant devices from the SIMATIC NET family can be monitored and operated via a
conventional standard Internet browser. The management system known as web-based
management offers a wide range of device-specific information (network statistics, status of
redundant supply, for example).