PLS - Physical Layer Scrambling
Physical Layer Scrambling or PLS is used in DVB-S2 as a way to improve data integrity. A number called the "scrambling sequence index" is used by the modulator as a master key to generate the uplink signal. This same number must be known by the receiver so that demodulation is possible.
Most satellite transponders use PLS 0 as a default value but there are some transponders that use other values.
Unidentified DVB-S2 satellite transponder
We press F2 and enter the corresponding PLS sequence number
After entering the PLS sequence number, the satellite transponder has been locked
Now the instrument is able to decode the picture and audio