How can I do an "atomic" bit write using the write_tag() about pycomm

[ruscito]

Not really sure what are you asking, but you can use "write_tag" to write a boolean

[gman8a]

see AB Control logic manual

URL: http://literature.rockwellautomation.com/idc/groups/literature/documents/pm/1756-pm020_-en-p.pdf

page 30

Read Modify Write Tag Service
The Read Modify Write Tag Service provides a means to modify Tag data with
individual bit resolution. Within ControlLogix, the Tag data is read, the logical
or modification masks, or both, are applied, and finally the data is written back to
the Tag. It can be used to modify a single bit within a Tag without disturbing
other data. Its purpose is similar to the PLC-5 style Read Modify Write PCCC
command described in Chapter 5

[gman8a]

I see the Read Modify Write Tag Service (0x4e) was not implemented.

[ruscito]

gman8a yes you are right Read Modify Tag Service is not implemented yet; I will take a look, but at the moment I'm focusing more to handle STRING datatype correctly

Thanks
Ago