1) When you transfer a new program to the PLC (say a blank program) the old program will automatically be wiped out.
2) As for the non volatile memory accessible by SAVE_EEPROM, you can run a small FOR NEXT loop to clear out everything:
E.g.
FOR I = 1 to 6000 ' all User FRAM data for Fx PLC
SAVE_EEP 0, n ' clear all the FRAM to 0
NEXT
3) If you are using the retentive parameters by turning on DIP switch #1, simply turn it off and do a power on reset to clear the retained memory data (A to Z, A# to Z$ etc).
4) You may also want to reset the Ethernet parameters. You can go to iTRiLOGI and select "Controller" -> "Ethernet & ADC Configuration" and then click "Factory Default" which will populate all the fields with default data. Then click "Save Parameters to PLC" button to transfer the settings to the PLC.
5) One more area to reset is the server file space where you may need to use FTP client software such as FileZilla to transfer either the default web app (
http://www.triplc.com/yabbse/index.php?board=2;action=display;threadid=2090) or your own webapp to the PLC.
Once you have covered the above the PLC would pretty much be set back to the factory default settings.
