The first feature I added to qastrocam-g2 was the ability to produce text files storing all the autoguiding corrections.
To produce this file, just choose "File" as a dummy telescope. These files are formated like Iris files, and thus can be
processed with PEAS.
So have a look to my EQ5's Periodic Error (1st generation, without ballbearing).
Rather regular, isn't it ?
Best regards !