How to pack / unpack single `BIT`s in PDO `input` / `output` about pysoem HOT 3 CLOSED

I've pretty much figured this out now, mostly through lot's of trial-and-error.

So in a nutshell: the PDO input and output is packed in a way I can't deduce from the EL7041 documentation, but I can copy the information from the TwinCAT project.
When clicking on an entry, e.g. "Sync Error", there is the "address" field. For this entry the address "40.7". The .7 indicates bit number 7 is being used (the last bit, because counting starts at 0). The 40 indicates the byte number, although it starts at an offset. The lowest address value is 39, so I'm considering address 39 as byte 0, 40 as byte 1, etc. So we can follow this to determine the entire PDO entry.

ctypes.Structure bit fields are well suited to this. See https://docs.python.org/3/library/ctypes.html#bit-fields-in-structures-and-unions

A complete example can be found in my comment here: #135 (comment)

from pysoem.

Nice job, this is great example.
Can we close this issue?

from pysoem.

Yeah, we can close this. I'm assuming there is not a less tedious and manual approach to this that I don't know.

from pysoem.