General tab
The general tab contains information and some per-adapter global configuration.
Add DVB Network by location...
Pressing this button will popup a window that allows the user to select a DVB network based on location. The adapter will be populated with multiplexes from these networks and immediately start to scan for services.
Map DVB services to channels...
Pressing this button will start a process that scans all services on all multiplexes and tries to verify if the service is actually a working TV channel. If so, the channel will be created and mapped to this service. You can start mapping services to channels once all muxes have been processed. Until then the option will be disabled.
Adapter name
You can change the display name for the adapter.
Autodetect muxes
The DVB transmissions contains information about other muxes available on the same network. If this checkbox is enabled, Tvheadend will automatically create new muxes as it receives configuration for them via the DVB networks.
Idle scanning
When nothing else happens Tvheadend will continuously rotate among all muxes and tune to them to verify that they are still working. If your adapter have problems with lots of tuning, try to disable this.
Detailed logging
If this is enabled, Tvheadend will log more information related to this specific adapter. You might wanna enable this if you have some kind of issues in order to better diagnose the problems.
Multiplexes tab
All multiplexes on the currently selected adapter are listed and can be edited in a grid. The columns have the following functions:
Enabled
Uncheck this if a multiplex is of no interest to you or otherwise temporary broken
Network
Network name as given in the DVB stream. Can not be changed
Frequency
Center frequency for the mux. Can not be changed
Modulation
Information about the modulation used on the mux. Can not be changed
Mux id
Unique ID for this mux in the dvb network. Can not be changed
Quality
Tvheadend's estimated quality for the mux.
Services tab
All services on the currently selected adapter are listed and can be edited in a grid.

The columns have the following functions:

Enabled
Uncheck this if a service is of no interest to you or otherwise temporary broken
Service name
Service name as given in the DVB stream. Can not be changed
Channel name
Double-click on this column to map the service to a channel.
DVB default charset
According to "ETSI EN 300 468", the default character set for EIT data is ISO6937. Unfortunately, some broadcasters actually use ISO-8859-x encodings but fail to correctly announce it. To fix this you can set the default charset to use when none is specified by the broadcaster.
EIT
Uncheck this if EIT data should not be retreived for this service.
Type
Type of service. Can not be changed
Provider
Provider as given in the DVB stream. Can not be changed
Network
Network name for the mux this service resides on
Multiplex
Center frequency for the multiplex this service resides on
Information button
Press this to get a popup with more information about the service

A word about DVB adapters

A DVB adapter represents a piece of hardware attached to the system. DVB receivers with dual tuners will present themselves as two adapters to the Tvheadend application. Tvheadend support DVB-T, DVB-C and DVB-S adapters.

There is currently no way of adding a new adapter to Tvheadend when running. If a new adapter is plugged into the system Tvheadend needs to be restarted in order to detect it.

If Tvheadend has configuration for an adapter and the adapter is missing upon start-up the configuration will be left untouched in case the adapter will be back in the future. There is currently no way to remove configuration for a no longer present adapter.

Warning: Unplugging an DVB adapter (USB, etc) during operation (i.e when Tvheadend is running) can result in deadlocking the kernel USB subsystem, most likely requiring a system restart.

Warning2: Suspending a system is (from a USB driver perspective) equivalent to a unplug/insert event. Thus, suspending a system running Tvheadend with USB adapters is not recommended at the moment.