Starting Sensor and Hardware Nodes

[Supported sensor](https://help.polysync.io/releases/2.0.8//sensors/) and hardware nodes defined in the SDF Configurator are typically spawned by the PolySync manager. However, in other cases─such as debugging a particular node─it may be better to manually start up one node at a time. Once a node has been defined it can be run standalone by referencing the node ID, pointing to the nodes configuration within the SDF. ### 1. Starting sensor and hardware nodes The PolySync manager should always be running before starting other nodes: ```bash $ polysync-manager ``` To spawn a single node, you must first know the _node ID_ located in the upper-right corner of the SDF Configurator. ![Node ID in the SDF Configurator](https://help.polysync.io/releases/2.0.8//wp-content/uploads/2016/07/polysync-sdf-configurator-node-id.png) The _node ID_ can then be used as an argument to the PolySync dynamic driver node. #### 1.1 Hardware state The node is expecting the physical hardware to be connected and communicating based on the IO Configuration parameters in the SDF. ```bash $ polysync-dynamic-driver -n 1 ``` #### 1.2 Replay state The hardware does not need to be connected in the replay state. The node will be in the standby state until it's instructed to quit or replay a logfile session. ```bash $ polysync-dynamic-driver -n 1 -w ``` Debug and error output is written to `stdout` and the file `polysync/polysync.log`. The node is stopped by issuing the `SIGINT` command, or pressing CTRL+C. #### 1.3 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](https://help.polysync.io/releases/2.0.8//articles/system-state/) module, and use the provided Studio plugins to visualize and validate the data. #### 1.4 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. ```bash $ polysync-dynamic-driver -n 1 -d ```