the two green lights are POK=power ok, PR=plc run. The CP light would be flashing because the plc is communicating, if it is not flashing it is ok.
the difference between connecting to x101 and x122 is the speed and type if you do not have the correct speed settings you cannot connect to the x122 ports.the picture shows x101 is 1.5mbaud x122 is 187.5kbaud. the difference in type also show in picture is OPI or MPI so you would change your driver in pg/pc interface to mpi or opi. The purple cable is the profibus cable it would need to stay attached as is, when looking at the ncu box the connection on the right will go to the operator panel and hmi only, the cable(if any) would goto the i/o, there is also a "fast i/o" port x111. You also must have the 840d toolbox installed to step7 or you will not be able to communicate with the plc on the nc card, this may be your problem.6FC5252-0AX21-0AB1 i think this is the number for the software but you should ask your siemens rep