reading the program from pic

Hi All,
We are using a legacy PIC board for controlling an level controller system. I want to get the program of it. We do not have the code or hex file. But I have to change the levels for new liquids and measurements. Is it possible to read the hex file that is programmed into the PIC microcontroller? How to get it?

Thanks.

Hi,
As long as the PIC doesn't have its code protection bit set you should be able to read it with a suitable PIC programmer you are using. The result will be .hex file which, in itself, won't do you much good. It's possible to disassemble the .hex file to get an assembly listing of it but there will be no comments, no variable names, no labels and so on. You would really need to know what you're doing in order to make changes in there.