[Modbus] Explaining data types

[egekorkan]

We should explain the mapping of the xsd types to what Modbus libraries would understand, i.e. saying that xsd:int is signed integer 32-bit.

[Kaz040]

I looked into the payloadDataType and I think the list of the xsd types in the binding template should be edited. I think data types like xsd:decimal and xsd:integer should not be included because they both have no limit (-infinity to infinity) plus they are used to generate other built-in-types that are limited(see the image below).

Also, since a register in modbus is 16 bits long (2 bytes), is there is any modbus implementation that will use a byte datatype? The same thought goes for unsignedByte

Lastly, I think we should make provision for timestamp datatype. some implementation might use it.

[danielpeintner]

FYI: the type hierarchy can be found here