EL: How to Detect Data Gaps?

["ndtrader" <ndtrader@xxxxxxxxxxx>]

How do you write a condition that is True when a bar of data is missing?

Let's say we have Data1 (no bars missing) and Data2 (with some bars
missing).

The following does *not* work:

DataPresent=C of Data2<>0 or C of Data2=0;
DataMissing=DataPresent=False;

When Data2 has a bar missing, DataPresent is not False; it just takes no
value.

Does anybody know what might work?

Thanks for any suggestions.