Can you write to modbus words at the bit level?

[boardmaker]

Archie,

Wondering if you can write to Modbus words at the bit level?  I know you can read them.

[Archie]

Only if the device supports function code mask write

http://www.mesulog.fr/help/modbus/index.html?page=mask-write-registers-f22.html

Otherwise you need to read the word, modify the value, then write it back and hope it didn't change in the process