Hi, All zennoposter logs are at: C:\Program Files\ZennoLab\EN\ZennoProjectMaker V7\7.7.1.0\Progs\Logs
Your path can be a little different based on your zenno version and program type. But it should be pretty similar.
But you can also use your own logs. Just make a file where you enter logs and save them there, by your own rules.