Datasource: SNMP

The SNMP Data Source allows efficient bulk reading from SNMP service and populate the Tags to be used in the Project.

The SNMP Data Source requires SNMP service to be running on the remote machine and configured correctly. Sym3 connects to the SNMP service using “public” community name which should be added to accepted community name in the service.

Create a new Data Source

A Data Source can be defined in Sym3, right click on Project Explorer > Data Sources then select ‘SNMP’ from the ‘New Source’ menu.

Note: Browsing is not supported for SNMP Data Sources.

Setting Up The Data Source

The property panel of the data source contains a few parameters that need to be set up for reading:

  • IP: IP address of the remote machine.
  • Request Rate (ms): How often (in milliseconds) this data source should update tags from remote SNMP service. Please note that a tag’s individual update rate is ignored by the SNMP data source.
  • Tags Per Request: The number of tags to update on each request update interval. This value can be set from minimum 1 to maximum 25.

Addresses are the SNMP Object Identifiers (OIDs).

Read Behavior

Here are the rules Sym3 follows when reading to a tag from the SNMP data source:

  • When the SNMP data source connects, at first it verifies each tag in individual requests at the given request rate.
  • When a tag is not verified, the status of that tag will be set as “BAD”, and it will not be included in the request until Simulation / Server restarts.
  • After all tags are verified, the SNMP data source will bulk update tags in individual requests based on Tag Per Request set by user.
  • On every request interval when previous request is not completed, the status of the tags for the previous request will be marked as “BAD_REQUEST_TIMEOUT” and those tags will be verified again on individual requests.
  • In the case where all the tags show “BAD_REQUEST_TIMEOUT” status, it’s possible that the SNMP service is not enabled or the remote host is unreachable.

Example

This is a simple examples which reads a few tags (OIDs) from a local SNMP service and updates their live values. The SNMP service must be enabled on local machine to successfully run this project.