Hi, "Collection tool is not available" here means one of the software/application viz DSET is not available.When you tested DSET via iDRAC was that from the same SupportAssist server? Can you send me a screenshot of the programs and features installed on the SupportAssist server? Also, Please make sure that all the connectivity tests are working in SupportAssist. Connectivity tests can be found in the top right corner of SupportAssist UI under Administrator or your Username. Please send us the SupportAssist logs from "C:\Program Files (x86)\Dell\Dell Integrated Support\logs" along with the screenshot.RegardsAniruddha S 
Dear All, I have tested DSET log collection via iDRAC, go Supportassist devices tab, and checkbox R720 Server(managed by iDRAC), and send system logs button. the messages shows "collection tool is not available" What's the problem? I already registered hosts file, and devicename/ip address can be resolved. 
Can not collect logs from SupportAssist