| If a PLC variable is out of range under
some conditions, Citect may not be able to write to it. Whenever
Citect tries to write to a PLC variable, it checks that the write
is in the correct range (as specified in the Variables database).
However a bug in the Cicode engine would mean that any range error
before a write would stop the PLC write. For example:
Temp = PLC_VAR;
PLC_VAR = 50; ! valid PLC write
If the PLC_VAR is currently out of range, when Cicode moves it
into the Temp variable it will be scaled. As the variable is out of
range it will generate a hardware error 'Value is out of range'.
When the Cicode tries to write 50 to the PLC_VAR, it will see that
there is a range error pending and will not write to the
variable. |
