In most cases the values that are provided by the database or OPC source are directly imported into the model. However, some values may need to be transformed. For example, while the model has pipe properties of OPEN and CLOSED, the file may contain 1 for open and 0 for closed. Alternatively, the SCADA system may not track run status as ON or OFF, but instead an operator simply views the flow from the pump and if the value is substantially larger than zero (allowing for drift), then the pump is considered on. In these cases, the user must indicate how to map raw signals to values the model can understand. This is done by picking the Signal Values Mapping tab from the top of the Database source manager.

This opens up a dialog, where the user can specify the mappings. There are two types of mappings, Single value where a specific SCADA value is mapped to a model property and a Threshold where a model value is inferred based on an inequality. For example, in the dialog below, if the flow is greater than the threshold value of 0.01, then the pipe is treated as being Open. Otherwise, it is considered Closed.

A value must be specified on the first row for any mapping. The second row, by default, is set to <any other value>. The user can explicitly override the "any other value" with a specific value.

Mapping using "single value" might fail. In this case the signal value is reported as (N/A). For example the Pipe Status mapping below will yield in a signal value of (N/A) for raw values that are not 0 or 1.

Note: the signal preview does not consider mappings. It is a view on the plain signal data.

When mapping are used and the user views values, there will be two values displayed in the SCADAD Signal Preview: the signal raw value and the signal value.

One special case is that of importing pump status as On or Off in the data source. One would think that it doesn't need a mapping since On/Off is what is displayed in WaterGEMS/CAD. However, internally the model stores 0 (On) and 1 (Off) so that it is necessary to map On to On and Off to Off as shown above.

Also see SCADA Signals - Database