Manually Starting Nodes Defined in the SDF

This article was written for version 2.0.9 of Core. Click here for the most recent version of the help center.

For many operations in PolySync, using the PolySync manager to automatically start all nodes that are defined and enabled in the SDF makes the most sense. However, in other cases─such as debugging a particular node─it may be better to manually start up one node at a time.

1. Getting the node ID

Start the SDF Configurator.

$ polysync-core-sdf-configurator

Next you will get the ID to start the node.

Each node─located in the list on the left─has a box indicating which ID this node is associated with. Save this ID for the next step.

SDF Configurator node ID

2. Manually starting a node

Before any other node is started, start the PolySync manager.

$ polysync-core-manager

Now that the unique node ID is known, start up the node using the PolySync provided dynamic driver.

$ polysync-core-dynamic-driver -n 1

This will start up the node in the terminal, and then block, as long it is in normal operation. Take a look at this document to get tips on more of the operations that the PolySync Dynamic Driver can perform.

It is possible to start multiple nodes. You just needs to open up a new terminal and run the Dynamic Driver with the unique node ID.

Additional information is written to the PolySync log file. This info can help to figure out why a node may not be working, or to check on normal operation. The log file can be “tailed” to capture the output of the dynamic-driver in real time:

$ tail -f ~/.local/share/polysync/polysync.log 

The node is stopped by issuing the SIGINT command, or pressing CTRL+C.

2.1. Validating the node data

Once the node has started it will begin publishing data to the global PolySync bus. This allows other applications to access the data by subscribing to the message types output by the node.

Start Studio to check the runtime status of the node using the System State module, and use the provided Studio plugins to visualize and validate the data.

2.2 Additional debug information

All PolySync provided sensor nodes support the -t flag which performs a test-operation on the hardware configuration, and the -h flag which prints out useful help info and configuration data specific to the specified node.

Most nodes support the -d debug flag to print debug information to stdout while parsing, processing and publishing data to the bus.

$ polysync-core-dynamic-driver -n 1 -d

3. Start all nodes

To see the process of starting all enabled nodes defined in the SDF Configurator, see the starting sensor and hardware nodes article, or the replay a logfile session article.