Greetings Barry ...
regarding your questions:
If Branch B had another branch level - would this execute and update bit status before analyzing Branch C?
if I understand your question correctly – then the answer is yes ... but you might want to post a sketch of what you're asking just to make sure that we're thinking along the same lines ...
Also, I notice how you did not give the status of the lamp until the very end of the scan - does this mean even though the bit status of O:6/0 is 1, the local output is not updated until the end of the scan
in simplest terms – the answer is "yes" ...
but ...
getting technical - it really depends on the type of processor being used ...
the OP seems to be using an Allen-Bradley MicroLogix 1500 – and the processor that I used in my analysis was an Allen-Bradley system along the same lines – specifically, one programmed using RSLogix500 - or maybe even RSLogix5 software ...
but ...
for the newer ControlLogix and CompactLogix systems (which are programmed using RSLogix/Studio 5000 software) the same "simple" answer wouldn't quite cut it ... because for those systems the status of the output bit/box can be sent to the output module at ANY point during the scan of the ladder logic – specifically, not just at the END of the ladder logic ... in simple terms, the newer systems don't have the same "under the hood" operation as the old-faithful platforms ...
and if so, does this mean in theory that it is possible for an output bit to be toggled on and off in a single scan without ever turning on its real world counterpart?
yes, it's completely possible – and not just in "theory" – but also in "reality" ...
if you'd like to read more about this subject, check out the Email Quizzes on my website – specifically, Quiz #110 ... download the PDF file for the Questions – and give it your best shot ... and then download the separate PDF file for the Answers and see if you came up with the right solutions for the SLC-500, for the PLC-5, and for the ControlLogix platforms ...
you can find the quizzes on the same page as the Sample Lessons and Videos – just scroll down a little bit past the videos to find the link ...
party on ...