Specifications

Web GUI Monitoring & Control
Figure 4.11: Configuration Main Window
4.7.2 Input Data Type
This is the method of locking to the incoming data.
4.7.2.1 VBR
Variable bit rate mode will add Mpeg Null packets to guarantee a fixed symbol rate. The data
rate has to be set to SPS, not BPS. The PCR values are re-stamped to meet the PCR jitter
requirements. The reset on error tick box is only valid in this mode. If this box is ticked and the
input is removed then the output will be disabled - otherwise null packets are transmitted
continuously.
204 byte Mpeg packets are automatically accepted and converted to 188 byte packets, the bit
rate assumes the transmission of 188 byte packets.
4.7.2.2 Normal
The transmitted carrier is frequency locked to the input data rate. The data rate can be set as
BPS or SPS and the calculation is performed. This operation acts as a seed and the actual symbol
rate is reported in the status window. The data stream is not modified. In DVB-S2 the data will be
transmitted as Transport streams and sync detection is performed.
The VBR on Error tick box will only appear in this mode, when the input is removed and the box
ticked then Null packets will be transmitted until the signal is replaced.
204 byte Mpeg packets are automatically accepted and converted to 188 byte packets, the bit
rate assumes the transmission of 188 byte packets.
4.7.2.3 Unframed
In DVB-S mode the data is required to be in a MPEG transport stream format i.e. a 0x47 Sync
mark every 188 bytes. In Unframed mode a sync mark is inserted which needs to be removed
within the demodulator. In DVB-S2 the data is transmitted without modification and no sync
detection is performed. The data will be transmitted as Generic Stream Continuous.
SBM75e Series Modulator Installation and Operation Manual
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