Hello,

I am reading AnalogItem nodes with EURange properties in my custom OPC UA Client that uses the Prosys OPC UA SDK for Java.

The Range objects from the server have null Low/High values, as shown in the Prosys Simulation Server browser:
https://i.snipboard.io/pASd0y.jpg

In my Java code, I read the Range like this:

In my Java code that looks like this:
“`
DataValue dataValue = client.readValue(nodeId);
Object value = dataValue.getValue().getValue();
if (value instanceof Range)
{
Range range = (Range) value;
Double low = range.getLow(); // Returns 0.0, expected null
Double high = range.getHigh(); // Returns 0.0, expected null
}
“`
The values being returned by the SDK’s Range.getLow() and Range.getHigh() methods are 0.0 instead of null. See debugger screenshot here:
https://i.snipboard.io/wTR8KE.jpg

Interestingly, range.toString() shows Range [Low=”0.0″, High=”0.0″] rather than Range [Low=”null”, High=”null”], confirming the SDK has already converted null to 0.0 during decoding.

My questions:

1. Is this the expected behavior when the server sends null Double values in a Structure?
2. What would be the right way to identify when the Range Low/High values are actually null vs. intentionally set to 0.0?
3. Is there a way to access the raw encoded data or status to detect null fields before the SDK converts them?

We need to distinguish between “no range specified” (null) and “range is 0 to 0” (valid) to properly configure alarm limits on our control points.

SDK Version: 5.4.0-201
Server: Prosys OPC UA Simulation Server

Thanks.
Mithun,
Tridium Inc.

Thanks.