For the GPS PPS to properly work on BOX systems, the following setting must be set correctly in the DSSupportTool.
If SBOX and SIRIUS are set as BOX solution (i.e. integrated slice on top of SBOX and R1, R2, R4, or R8) and the SBOX has:
a) no GPS -> External PPS must be selected
b) built-in GPS -> External PPS must not be selected