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](../../assets/images/news/375-picture1.gif)
Unidentified DVB-S2 satellite transponder
![We press F2 and enter the corresponding PLS sequence number](../../assets/images/news/375-picture2.jpg)
We press F2 and enter the corresponding PLS sequence number
RANGERNeo + and RANGERNeo Lite field strength meters are compatible with this type of signals. The PLS sequence number can be entered under F2 as shown in the above right picture.
![After entering the PLS sequence number, the satellite transponder has been locked](../../assets/images/news/375-picture3.jpg)
After entering the PLS sequence number, the satellite transponder has been locked
![Now the instrument is able to decode](../../assets/images/news/375-picture4.jpg)
Now the instrument is able to decode the picture and audio
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