I'm interfacing a device over the Modbus protocol.
There's commands for reading and writing registers (register = 2 bytes).
However, often a register contains multiple config flags as bits, and I need to write just one of them or so.
I could read it, modify flag and write it back, but is that the right way?
I've seen some commands for writing coils, but I'm not really sure what a coil is - is it a bit? If so, how do get address of a coil?