By default, the Connector List generates automatically, and the Build Connector List button is not visible. If NETS settings are set to disable automatic Connector List generation, click the Build Connector List button to generate the list of Connectors found in the Test Script. When testing large assemblies, vehicles, or tests with many connectors, disabling automatic Connector List generation may be desirable to reduce time spent initializing the Test Script.
Source: NETS User Manual, Revision D, document 132-06035-0006, section 6.2.