DMX polarity switch

[N_Cook]

If someone changed the polarity by changing the switch at the rear of a
lighing controller what would be the result?
Assuming fully working order beforehand.
1 no lamps controlled
2 erroneous lamps controlled and erroneous control
3 correct lamps but erroneous control

would a symptom of erroneous control be say by sliding up the blue content
then G and or R component of lighting drops

 

[N_Cook]

Something like situation 3 - maybe a bit garbled, in
phone call about "broken" controller , but someone had flipped the switch on
the back