feat: Add set_coil and set_register

[zhongys-c8y]

Added set_coil.py and set_register.py under tedge_modbus for writing values to modbus. One for register, one for coil. In the reader.py, added on_message function to subscribe to the tedge local MQTT topics of child devices' operations. The operation payload was based on the internal docs 'cloud fieldbus specification'. The c8y operation will be first mapper from c8y/devicecontrol/notifications topic to tedge local topics by using tedge custom operation template.

It was tested with the simulator in this project. It can successfully change the register and coil value.

[github-actions]

Robot Results

✅ Passed	❌ Failed	⏭️ Skipped	Total	Pass %	⏱️ Duration
22	0	0	22	100	41.379714s

Passed Tests

Name	⏱️ Duration	Suite
Device should support the operation c8y_ModbusConfiguration	0.106 s	Device
Set values via c8y_ModbusConfiguration Operation	2.335 s	Operation
Poll rate and transmit rate should be updated for the Device	0.192 s	Operation
Poll rate and transmit rate should be updated on the Device	2.330 s	Operation
Device should support the operation c8y_ModbusDevice	0.105 s	Device
Device should support the operation c8y_SerialConfiguration	0.108 s	Device
Set values via c8y_SerialConfiguration Operation	2.325 s	Operation
Serial configuration should be updated for the Device	0.196 s	Operation
Serial configuration should be updated on the Device	2.324 s	Operation
Device should have installed software tedge-modbus-plugin	0.142 s	Debian
Service should be active	2.329 s	Debian
ReInstall Modbus Plugin	22.672 s	Debian
Device should have the fragment c8y_ModbusConfiguration	0.209 s	Device
ChildDevice TestCase1 should be created	0.201 s	Device
ChildDevice TestCase1 should have the fragment c8y_ModbusDevice	0.503 s	Device
Service tedge-modbus-plugin should be enabled	0.103 s	Device
Device should set supported operations for writing to registers and coils	0.099 s	Operations
Device should write to a registers	2.351 s	Operations
Device should write to a coil	2.339 s	Operations
ChildDevice TestCase1 should have a Test.Int16 Measurement	0.204 s	Telemetry
ChildDevice TestCase1 should have a Test.Float32 Measurement	0.205 s	Telemetry
ChildDevice TestCase1 should have Alarms of type TestAlarm on Coil Value 1	0.001 s	Telemetry

[reubenmiller]

@zhongys-c8y Can you run the formatting and linting and address any of the reported issues?

just format
just lint

[rina23q]

Need to be changed a bit.

[zhongys-c8y]

Added tedge_modbus/operations/topic_switcher.py to map the messages from c8y/devicecontrol/notifications to te/device/<childdevice>///cmd/<operation> topic. Please check the .template files for it, not sure if I wrote it in the right way.

[zhongys-c8y]

Now the set_coil and set_register operations will be mapped from c8y/devicecontrol/notification topic to /te/device////cmd//# topic. Added a topics-subscriber in reader/reader.py which will react to these two topics and call operation/update_register.py and update_coil.py to write the register and coil.

[zhongys-c8y]

TODOs:

1. Need to publish 'te/device////cmd/command' '{}' for each child modbus device.
2. Need to know how to change the operation status of a child device's operation.

[didier-wenzek]

I confirm the interactions between the plugin and thin-edge are correctly implemented

[reubenmiller]

Do we need this file? It doesn't seem to be providing any value

[zhongys-c8y]

No, also only for my local test, I should not publish it