The item in the [Targets] section called HexFileName01 is the file name of the hex file that contains the firmware that will be programmed into the target processor to perform the upgrade.

In our example, this file is called AryTst5_2550.hex.  The file name contains the suffix "_2550" to emphasize the fact that your firmware must be compiled to work in the same target processor that is specified with the TargetID.