The default is 60 seconds and can't be changed through the GUI.
We had issues with the SCCM client causing Windows Updates to fail, so rather than push a solution through SCCM, I pushed it through PSEXEC. Here's the batch file solution.
When this is launched, it triggers the SCCM agent to launch it's discovery and reporting processes. It's similar to what happens when you use the SCCM control panel icon on a workstation, and click all the processes.
This looks for systems that don't seem to be doing their SCCM Agent work, but aren't complaining.
This looks for systems that are having trouble completing SCCM deployments.