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source is a CODED ENUM (SourceKind) and can have two values
type SourceKind | |
|---|---|
0 | process |
1 | substituted |
The server IED that is hosting the data can decide how to use this bit string. Its meaning is indicating that data is coming from a real process or is substituted somehow. One application field for this procedure is interlocking. To calculate the signal whether a switch gear is interlocked, input (position) from various switchgear is needed. Imagine one of the inputs is not sent for whatever reason. In this case you still need to set a default (you want to substitute) and then want to indicate that the outcome of the interlocking is based on a substituted value. The above source allows you to do so.
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