Table 5.

Description of protocols for individual steps.

Step	Protocol	Description
Waiting for Start Signal	OPC UA	The MES system delivers a message to run the action on the IIoT device.
Capture Image	SPI	SPI Camera. This results from a hardware connection.
Save Image	HTTP	Outside storage of the IIoT device, save—REST call PUT method.
Resize Image	HTTP	Data are stored on external storage, resize—REST call POST method.
Analyse	HTTP	Data on the external storage, analyse—REST call POST method.
Make a decision	HTTP	Data are stored on external storage, decision—REST call POST method.
Switch gateway	OPC UA	Message to the MES system in order to set the gateway to the desired state.