hein holz

"--scan-bands" and "--scan-flags DVB-C" do exactly the same, only the syntax is different . No need to change anything
These options reduce the amount of frequencies scanned by cxd1978. The frequencies are hard coded.
 

root@dm7020hd:/# cxd1978 --init --scan --verbose --wakeup --inv 2 --bus 2 --scan-flags DVB-C:VHF II
failed reading revision from driver, default to 1
waiting for 1 seconds
FAILED 105000 8000000
FAILED 113000 8000000
FAILED 121000 8000000
FAILED 129000 8000000
FAILED 137000 8000000
FAILED 145000 8000000
FAILED 153000 8000000
FAILED 161000 8000000
FAILED 169000 8000000

root@dm7020hd:/# cxd1978 --init --scan --verbose --wakeup --inv 2 --bus 2 --scan-bands 2
failed reading revision from driver, default to 1
waiting for 1 seconds
FAILED 105000 8000000
FAILED 113000 8000000
FAILED 121000 8000000
FAILED 129000 8000000
FAILED 137000 8000000
FAILED 145000 8000000
FAILED 153000 8000000
FAILED 161000 8000000
FAILED 169000 8000000

Now I tested Cable Scan with Network id 61448. Result: It's searching a bit longer, but scanning failed!

Here is a part of my NIT. May be cable scan only works if Network_ID = Original_network_ID?

 dvbsnoop V1.4.51 -- http://dvbsnoop.sourceforge.net/ 

------------------------------------------------------------
SECT-Packet: 00000001   PID: 16 (0x0010), Length: 250 (0x00fa)
Time received: Sun 2015-05-03  15:47:18.639
------------------------------------------------------------

PID:  16 (0x0010)  [= assigned for: DVB Network Information Table (NIT), Stuffing Table (ST)]

Guess table from table id...
NIT-decoding....
Table_ID: 64 (0x40)  [= Network Information Table (NIT) - actual network]
section_syntax_indicator: 1 (0x01)
Network_ID: 61448 (0xf008)  [= Kabel Deutschland | 276 | Cable | Kabel Deutschland]
Version_number: 13 (0x0d)
current_next_indicator: 1 (0x01)  [= valid now]
Section_number: 3 (0x03)
Last_Section_number: 3 (0x03)

    Transport_stream_ID: 10016 (0x2720)
    Original_network_ID: 61441 (0xf001)  [= Deutsche Telekom | Deutsche Telekom AG]

            DVB-DescriptorTag: 68 (0x44)  [= cable_delivery_system_descriptor]
            descriptor_length: 11 (0x0b)
            Frequency: 55836672 (= 354.0000 MHz)
            FEC_outer: 2 (0x02)  [= RS(204/188)]
            Modulation (Cable): 5 (0x05)  [= 256 QAM]
              Symbol_rate: 430080 (=    6.9000)
            FEC_inner: 15 (0x0f)  [= No conv. coding]

            DVB-DescriptorTag: 65 (0x41)  [= service_list_descriptor]
            descriptor_length: 18 (0x12)
               service_ID: 50033 (0xc371)[ --> refers to PMT program_number]
               service_type: 25 (0x19)  [= advanced codec HD digital television service]

               service_ID: 50035 (0xc373)[ --> refers to PMT program_number]
               service_type: 25 (0x19)  [= advanced codec HD digital television service]

               service_ID: 50031 (0xc36f)[ --> refers to PMT program_number]
               service_type: 25 (0x19)  [= advanced codec HD digital television service]

               service_ID: 50032 (0xc370)[ --> refers to PMT program_number]
               service_type: 25 (0x19)  [= advanced codec HD digital television service]

               service_ID: 50034 (0xc372)[ --> refers to PMT program_number]
               service_type: 25 (0x19)  [= advanced codec HD digital television service]

               service_ID: 50030 (0xc36e)[ --> refers to PMT program_number]
               service_type: 25 (0x19)  [= advanced codec HD digital television service]

New Pli image 2015-05-03 on dm7020hd.

Tuner configured first for frequency bands, then frequency steps, then provider (Kabel Deutschland).

Automatic scan and manual scan (complete) : all ok

Then I tested Cable Scan with Network id 61441. Result: Scanning failed!

This doesn't work and it never worked.

Best and fastest method is Manual scan -> User defined transponder 466 MHz -> Network scan = yes.