Setting up our scenario
Our sample solution architecture is simple, and in line with most of the examples and use cases explored in this book. Figure 10.6 provides an overview of the layered architecture we have discussed in detail. The core of the activity is in layer 2 of our overall diagram, where we focus on edge computing and applications:
Figure 10.6 – Greengrass solution architecture
We have numbered the data flow and components within the environment to illustrate how functions are triggered, and how data flows within the activity sequence. We can describe the activity as follows:
- Request Data: This component, called the Modbus Request, is a custom Python function that runs in a continuous loop. This process wakes up and triggers a message every few minutes, telling the Modbus component to query the PLC and retrieve some data.
- Query the PLC: The Modbus TCP component performs both steps 2 and 3. Based on the request from step...
