IOS SDK Testing _ Console logs of ios app truncate and unable to fetch from console window

Case : After 20-30 iteration of test cases of iOS SDK , logs are being auto stopped to occur on console app, due to this reason i am unable to verify the logs in sequential manner.
i am reading the logs which are fetched in log-cat command.

any workaround available for read and fetch the logs continuously for about 200+ iterations ??