Dear John.
The UP-arrows are indicating that there is an overflow for the specific value.
Each digit for BCD - code has a value range from 0 to 9. It's the only range which makes
sense and defined in the vizualisation and linked to marker bytes.
With 4 bits you are able to set values from 0 to 15 but everything from 10 to 15 is out of
range. If you activate inputs I3 and I4 you already will see the "overflow arrow". The
Moeller example is programmed without range check.
Regarding the analogue inputs IA please take into account that analogue and digital
inputs are related. For example IA1 is the same as I7 and used as analogue or digital type
only depending on the program. An input I7 = high is the same as IA1 = 10.0 V and vice versa.
In case the explanation is too general please let me know.
Regards Maikky