An ioControl strategy with two PIDs that reference each other may cause an ‘Undefined command’ error when the strategy is downloaded.
The order in which the PID loops are defined by ioControl, and the order in which the PIDs reference each other, causes the download error. The PID loop that is referenced by another PID is not configured/compiled before the PID that references it is compiled.
For example, in a strategy, there are two PID loops named Reheat_2_Inner_Loop and Reheat_2_Outer_Loop. Reheat_2_Inner_Loop references Reheat_2_Outer_Loop. The ioControl compiler will compile Reheat_2_Inner_Loop first (it alphabetically is identified first).
Rename the PID loops so that the PID loop that is referenced by another is compiled first.
In the above example, renaming the loops in the following manner will work around the problem:
Opto 22 is researching this issue.