Python Block Tags

TODO:
 * use a threshold
 * set a tag when threshold exceeded
 * feed in a noise source (average it?)
 * tag blocker
 * block to read tag, then change the output
 * make a picture associating tags with samples

The previous tutorial, Python Block Message Passing demonstrates how to send and receive messages using the Embedded Python Block. The next tutorial, Low Pass Filter Example, demonstrates how to use filtering blocks in GNU Radio.

Tags Overview
Tags are a way to convey information alongside digitized RF samples in a time-synchronous fashion. Tags are particularly useful when downstream blocks need to know upon which sample the receiver was tuned to a new frequency, or for including timestamps with specific samples.

Where messages convey information in an asynchronous fashion with no clock-based time guarantee, tags are information which are associated with specific RF samples. Tags ride alongside digitized RF samples in data streams and vectors, including Complex Float 32, Float 32, Byte and all of the other formats.

More information about tags can be found here: Stream Tags

Threshold: Writing the Tags
The next tutorial, Low Pass Filter Example, demonstrates how to use filtering blocks in GNU Radio.