Introduction to Networking

A PolySync Core host is defined as any ECU or machine processing PolySync Core applications. The applications include:

  • PolySync Core Manager
  • PolySync Core Studio
  • Dynamic Driver interface
  • Example application
  • Custom application

In all network configurations, applications and hosts communicate by publishing and subscribing messages to the PolySync Core bus. The PolySync Core bus exists on the physical Ethernet layer, and is accessible through the PolySync Core host’s defined IP address.

There are two network configuration paradigms that a PolySync Core host may fall under:

Network tuning and debugging

Add DDS logging

The PolySync Core data model uses the Data Distribution Service (DDS) which is a realtime data centric publish subscribe architecture. When extending the PolySync Core data model it will be usefull to add log messages during the development cycle.

Location of log files

When nodes are started with polysync-core-manager the files are located in the /tmp directory.

/tmp/ospl-info.log   # contains information and warning reports
/tmp/ospl-error.log  # contains error reports

When nodes are started on the command line the ospl-info.log and ospl-error.log files are created in the current directory.

Available logging levels

The log levels start with most verbose, and end with no logging.

  • DEBUG
  • INFO
  • WARNING
  • API_INFO
  • ERROR
  • CRITICAL
  • FATAL
  • REPAIRED
  • NONE

Change DDS logging verbosity

The DDS logging verbosity is controlled in the $PSYSNC_USER_HOME/config/dds.xml file.

$ cd $PSYSNC_USER_HOME/config
$ vi dds.xml

Add the following line in the Domain tag with desired verbosity:

<Domain>
    <Report verbosity="DEBUG"/>
</Domain>

The setting will take affect by stopping and restarting the node(s).

Troubleshooting

Failed to get DDS domain participant

The default maximum number of nodes is set to 20.

This error occurs when more than 20 nodes are running at the same time. 2017-01-06 20:36:24.01s ERROR [diagnostics-] - failed to get DDS domain participant - check installation

The maximum number of nodes is set in: $PSYSNC_USER_HOME/config/dds.xml.

$ cd $PSYSNC_USER_HOME/config
$ vi dds.xml

Increase the maximum number of nodes in the following tag:

<Discovery>
    <ParticipantIndex>auto</ParticipantIndex>
    <MaxAutoParticipantIndex>20</MaxAutoParticipantIndex>
</Discovery