general modbus entity/service

[Robbie-1208]

No description provided.

[wcpettus]

should remove slack_sdk from this PR (that's from your working code on slack integration)

[wcpettus]

@nsoblath : should we have these extensions flat in the dripline/extensions/ directory? or in their own subdirectory like jitter was (doesn't seem to add value)

[renereimann]

We should cross-compare and harmonize with #223

[wcpettus]

So you can only define the endian-ness of the word order and not the byte order now? I'm hoping this doesn't cause issues for any devices down the road. The documentation on the new method seems thin, with a lot of the docs still using BinaryPayloadDecoder despite the deprecation warnings, but that's a developer side issue.

Our device is offline right now, so can't test. Will have to work out any issues on a hot fix. I may go back and allow endianness to be defined at a Service level, since that should be a device property and not require specification at the individual entity level.

[renereimann]

So you can only define the endian-ness of the word order and not the byte order now? I'm hoping this doesn't cause issues for any devices down the road. The documentation on the new method seems thin, with a lot of the docs still using BinaryPayloadDecoder despite the deprecation warnings, but that's a developer side issue.

Our device is offline right now, so can't test. Will have to work out any issues on a hot fix. I may go back and allow endianness to be defined at a Service level, since that should be a device property and not require specification at the individual entity level.

According to the MODBUS Application Protocol (2012) see e.g.
https://web.archive.org/web/20250825211935/https://www.modbus.org/docs/Modbus_Application_Protocol_V1_1b3.pdf
Section 4.2

the endian-ness of the bytes is defined in the protocol standard. Therefore devices "should" have this implemented.
The endian-ness of the individual words is not specified and thus can be set. I agree that it makes sense if one device uses the same endian-ness for all parameters.

[renereimann]

@wcpettus I have implemented your suggestions and also made the wordorder again a service property. I fully agree that this just makes sense. Since also the test builds work and we have no conflict with develop we are ready to merge.