State of Atemp
What's the state of YHeat and YFan when the Atemp's state is inbetween 800 to 900, I think there the previous state of either of the YHeat or YFan is retained. This means say if Astate's scroll bar's pointer is at 0 and YFan is On then for a value of Atemp's state inbetween 800&900 the State of YFan still remains 1 and YHeat's state is still 0 but in the ladder diagram the rung of both conditions viz. YHeat(R)-YFan(S) and YHeat(S)-YFan(R) becomes deenergized. How is this happening where any one of the state is remaining retained as pe set only condtion or say reset only condition but the rung is deenergized for both cases when the scroll bar's pointer of Atemp state is inbetween 800-900.
OpenPLC-with-LDmicro A-to-D-Converter-Read-Instruction 04-05 min 20-30 sec
When Atemp state is in between 800 & 900, the both rungs are de-energized because the Atemp conditions in both rungs become false.
But since we are using SET and RESET coils to represent Yheat and Yfan, they tend to retain their state even when their input is 0. This is how SET and RESET coils works and it is explained in the respective tutorials.