Every task will log key events and errors to its own log file. Certain key functions will have log files with recognizable names, but most will have a name like "chan7_err_log". The number appended to "chan" is the task number. You can correlate this with the task list under Task Status or Task Configuration. The log files are primarily a trouble shooting aid.
All files in the logs directory will be included in the drop-down list at the top of the page. Simply select the file you want to see and it will be displayed.