Module to Module Communication

Module to Module communication refers to the direct exchange of data between AVEVA Edge adapter modules and the Edge Data Store (EDS) when they run on the same host. Instead of sending data through external networks or relying on host-level IP addresses, these modules share information internally through a Docker bridge network using the module (container) names.

When adapters are set up, they have to send data to the endpoint using either the host’s external IP or a full domain name. This helps make sure the data gets where it’s supposed to go by using these network details to connect the adapter with EDS. But on Edge devices, IP addresses can change after a reboot or network reset, and sometimes the local host might not work right inside a container.

Module to Module communication resolves these issues by utilizing the Docker’s internal bridge network, enabling containers to communicate with one another by name, independent of any modifications to the host network. This enhances the stability of communication channels.

The following diagram demonstrates the communication between AVEVA Edge modules—namely, the OPC UA Adapter module and the Edge Data Store (EDS) module—on a single edge device through a Docker bridge network. It also illustrates how the EMS Portal is involved in managing and deploying these modules.

In this diagram, the EMS Portal serves as the cloud-based management platform for deploying, configuring, and overseeing edge modules. It interacts with the edge device to provide container images and configuration files for the adapter and EDS modules. The Edge Host Machine operates Docker and serves as the platform for all deployed modules. Inside Docker, every container (module) is linked through a common Docker bridge network (in this example, azure-iot-edge).

The adapter_opcua_module includes an Edge Management Module that receives deployments and configuration updates from the EMS Portal. The OPC UA Adapter offers a configuration endpoint on port 5595. It sends OMF egress data to the EDS module through the bridge network.

The edge_data_store_module contains an Edge Management Module that also gets updates from the EMS Portal. The Edge Data Store service operates internally on port 5595. Additionally, there is an Nginx Reverse Proxy that provides a consistent endpoint on port 5590, enabling adapters to reliably send out OMF data.

Because both the adapter and EDS modules run inside the Docker and share the bridge network, the adapter can send data to http://edge_data_store_module:5590.

For information on how to troubleshoot module to module communication, see the Troubleshooting section.