When using the Oscilloscope tool in ACR-View, the software will automatically re-dimension memory to whatever "PROGx"is listed under the Motion button. The default is PROG0. When the Motion button is selected, there is a text field that says "Download Commands To PROGx when Run Button is Hit", and then you'd select the appropriate PROGx, which may result in overwriting your defined arrays if the program code that you are running.
For example, if you've written a program in PROG0 and declared some arrays, and are also using the Oscilloscope tool and the PROG0 that you've written and the Oscilloscope Motion box is also set to "Download Commands To PROG0 When Run Button is Hit", it will automatically clear out all arrays in your PROG0.
To prevent this, you'd select one of the PROGX that you aren't using. So if you have written a program for PROG0 and you are not using PROG1, change the "Download Commands To PROG1 When Run Button Is Hit".