Bug or misunderstanding of word_order in convert methods

[igorbga]

Look at this code:

from pymodbus.client.mixin import ModbusClientMixin


original_values = [1.0, 2.0, 3.0]
registers = ModbusClientMixin.convert_to_registers(
    original_values, ModbusClientMixin.DATATYPE.FLOAT32, word_order="little"
)

converted_values = ModbusClientMixin.convert_from_registers(
    registers, ModbusClientMixin.DATATYPE.FLOAT32, word_order="little"
)
print("Original values:", original_values)
print("Converted registers:", registers)
print("Converted back values:", converted_values)

I expected this result:

Original values: [1.0, 2.0, 3.0]
Converted registers: [0, 16448, 0, 16384, 0, 16256]
Converted back values: [1.0, 2.0, 3.0]

But got:

Original values: [1.0, 2.0, 3.0]
Converted registers: [0, 16448, 0, 16384, 0, 16256]
Converted back values: [3.0, 2.0, 1.0]

I thought the "word_order" was meant to be used in order to specify how words are ordered when decomposing datatypes with more bytes. For example in a 4 byte float that will be transmited as 2 words I expected "word_order" to determine if the first word has the least significant portion (little) or the most significant part (big).

But checking at the code I can see all it does is reverse all the registers or something like that.

I guess I'm just misunderstanding something...

[janiversen]

You do not write which version you are using ??

Apart from that, to_registers actually expect one value not multiple, in which case the regs.reverse() is correct.

It is correct that it could easily be changed to loop over multiple values, pull requests are welcome.