The following should work:
Create a script called "MyScript" with the following code:
node1 = FindNodeObject($node,"NODE1_NAME");
node2 = FindNodeObject($node,"NODE2_NAME");
dci1 = GetDCIValueByDescription(node1,"DCI1_DESCRIPTION");
dci2 = GetDCIValueByDescription(node2,"DCI2_DESCRIPTION");
return dci1 + dci2;
Replace NODE1_NAME and NODE2_NAME with the object names of the nodes holding your data.
Replace DCI1_DESCRIPTION and DCI2_DESCRIPTION with the DCI descriptions.
Create a new DCI on a node, select type "Script" and select the "MyScript" you created earlier.
You do not need to use a delta transform for this, as you already transformed the other two DCIs.
If you do not get any result, there may be a typo in one of the node names or DCI descriptions or you may have the trusted node check enabled (that's the default) and NODE1_NAME and/or NODE2_NAME do not contain the node you're running the script on in the list of trusted nodes. You can confirm if that's the issue by setting the server configuration variable CheckTrustedNodes to 0 and restarting the NetXMS server.
You can always just right-click on a node and "Execute Server Script" and select "MyScript" to see what's happening when you execute it.
Documentation references:
https://wiki.netxms.org/wiki/NXSL:FindNodeObject
https://wiki.netxms.org/wiki/NXSL:GetDCIValueByDescription
https://wiki.netxms.org/wiki/SG:Security_Issues
Cheers
