AS400 has its own object hierarchy. Files are mambers, stored in physical files that are created inside a library. For example a AS400 agent creates, feeds and handle his log files as member (UCEX_LOG0*) in the File TMP, itself created in a library for example UC4V11.
To sum up libraries, can be considered as directories, physical files as sub-directories, and members as conventional files.
If you want to retrieve the log files simply open a ftp connection to the AS400 in a DOS-Box.
Browse to the installation library of the AS400 agent
cd UC4V11
if you run a dir you wil get
ls
25 List started.
.......
DFTOWN 1290240 08/31/16 02:00:21 *FILE TMP
DFTOWN *MEM TMP.UCEX_LOG00
DFTOWN *MEM TMP.UCEX_LOG01
DFTOWN *MEM TMP.UCEX_LOG02
DFTOWN *MEM TMP.UCEX_LOG03
DFTOWN *MEM TMP.UCEX_LOG04
DFTOWN *MEM TMP.UCEX_LOG05
DFTOWN *MEM TMP.UCEX_LOG06
50 List completed.
Actually the AS400 naming rule of a member is <FILENAME>.<MamaberName>.
Retrieve all members
mput TMP.U*
Confirm each download with 'y'
These objects will be locally transferred on your local workstation and are now ready to be analyzed!!