For the Upload/Host-mode the IPS-STE have to be powered permanently, this is possible with a 12VDC supply at the "Input" (MIL-connector, round) and at the input "Control - pin: Enable" (D-Sub 9 connector). For the latter this can be done by shortening the "Enable (pin 1)" with "VINR (pin 5) at the "Control"-connector (D-Sub 9). For activating the Upload/Host-mode it is necessary to push and hold the "Power" button before feeding the 12VDC power, then supply the 12VDC voltage and after it release the "Power" button - now the IPS-STE Upload/Host-mode is active.
The upload itself will be done with "Run". For more informations please have a look to the manual, chapter 3.6 Upload and Debugging on the real IPS-STE (page 19).