Notes and Restrictions

SNMP (Simple Network Management Protocol) is a protocol for monitoring network devices. In SNMP there are two types of management units: managers and agents. The agents provide the information and the managers query it. The information is queried via the SNMP protocol.

In WinCC OA SNMP differentiates between the SNMP Pmon agent (integrated in PMON) and the SNMP live agent (API manager). The WinCC OA SNMP manager (driver) collects the data from external or internal SNMP agents.

If the data is collected from external SNMP agents, an alert can be shown in WinCC OA e.g. if some network device fails. In this case an agent of an external network device sends data to the WinCC OA SNMP manager. Furthermore, WinCC OA can be monitored via external network tools. In this case the WinCC OA data is sent to the manager of the external tool by the WinCC OA SNMP agent.

Note: In case of loosing the connection, the SNMP driver can set the data form the lost connection to invalid. This setting configuration can be done inside the config file. See also: mapInvalidData, delayBetweenAgents.

Requests for comments (RFCs)

For more information on SNMP see also the following RFCs:

  • 1175 (SNMP)
  • 2011 (SNMPv2 MIB for IP)
  • 2012 (SNMPv2 MIB for TCP)
  • 2013 (SNMPv2 MIB for UDP)
  • 2578 (SMIv2)
  • 2863 (Interface Group MIB)
  • 3414 (User-based Security Model (USM) for SNMPv3)
  • 3416 (SNMPv2)
  • 3418 (MIB for SNMP)