To install Dstv extra view with 2 HD decoder with Dstv Smart LNB, you need to link them in the installation wizard.
The video below demonstrates how to run installation wizard on 2 HD decoders
First Primary Dstv HD decoder
USER BAND TUNER 1 FREQUENCY ——– 1210
USER BAND TUNER 2 FREQUENCY ——– 1420
USER BAND TUNER 1 INDEX — 0
USER BAND TUNER 2 INDEX — 1
Second Dstv HD Decoder
USER BAND TUNER 1 FREQUENCY ——– 1680
USER BAND TUNER 2 FREQUENCY ——– 2040
USER BAND TUNER 1 INDEX — 2
USER BAND TUNER 2 INDEX — 3