doc: Rewrote the DLT user documentation.

- Write introduction and prepare new TOC
- Intro to Get Started, instructions on how to download and detailed TOC further
- Started Run DLT Demo section

Signed-off-by: Sebastian Unger <sunger@de.adit-jv.com>

4 files changed, 293 insertions, 130 deletions

diff --git a/README.md b/README.md
index e0c9936..98b1b04 100644
--- a/README.md
+++ b/README.md
@@ -4,28 +4,57 @@ Build and Test status: [![Build Status](https://travis-ci.com/GENIVI/dlt-daemon.
 Alerts: [![Total alerts](https://img.shields.io/lgtm/alerts/g/GENIVI/dlt-daemon.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/GENIVI/dlt-daemon/alerts/)
 Code quality: [![Language grade: C/C++](https://img.shields.io/lgtm/grade/cpp/g/GENIVI/dlt-daemon.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/GENIVI/dlt-daemon/context:cpp)
 
-## Overview
+# Diagnostic Log and Trace
 
-This component provides a log and trace interface, based on the standardised
-protocol specified in the AUTOSAR standard 4.0 DLT. This software can be used
-by GENIVI components and other applications as logging framework.
+Welcome to GENIVI Diagnostic Log and Trace (DLT). If you are familiar with DLT
+and want to know what's new, check the [Release Notes](ReleaseNotes.md).
 
-DLT basically consists of 3 components:
+**New to DLT? Great! Welcome aboard.** We prepared a brief [overview](#overview)
+for you as well as some information on how to [get started](#get-started)
+immediately. After you made yourself familiar with the basic mechanics of DLT,
+you can [learn more](#learn-more) about advanced concepts and features.
 
-- **DLT Library**: Enables DLT logging for DLT user applications and temporary
-  storage of log messages if daemon isn't available.
-- **DLT Daemon**: Receiving log messages from DLT user applications and
-  temporary storage of log messages if client isn't available. Transmit log
-  messages to DLT Client and response to control messages.
-- **DLT Client**: Receiving and storing log messages from DLT Daemon into one
-  single trace file and sending control message
+## Overview
 
-![alt text](doc/images/dlt_overview.png "DLT Overview")
+GENIVI DLT provides a log and trace interface, based on the standardised
+protocol specified in the
+[AUTOSAR standard 4.0 DLT](https://www.autosar.org/fileadmin/user_upload/standards/classic/4-0/AUTOSAR_SWS_DiagnosticLogAndTrace.pdf).
+It is used by other GENIVI components but can serve as logging framework for
+other applications without relation to GENIVI.
+
+The most important terms and parts are depicted in the following figure. Please
+refer to [Glossary](doc/dlt_glossary.md) for a full overview over DLT-specific
+terms.
 
-Furthermore, the repository contains several adaptors, console utilities as well
-as test applications.
+![alt text](doc/images/dlt_overview.png "DLT Overview")
 
-## Build and install
+- A **DLT User** essentially is an application that serves its respective (not
+DLT-related) purpose and produces DLT log messages. It utilizes the DLT library
+to craft and transmit these messages.
+- The **DLT Library** provides a convenient API to DLT Users (i.e. applications)
+to create DLT log messages and hand them over to the DLT Daemon. If the latter
+is not avilable, the library will cache the messages in a ring buffer so they
+don't get lost immediately.
+- The **DLT Daemon** is the DLT communication interface of an ECU. It collects
+and buffers log messages from one or more DLT users running on the ECU and
+provides them to DLT clients upon their request. The daemon also accepts control
+messages from the clients to adjust the daemon's or the aplications' behaviour.
+- A **DLT Client** receives and consumes the log messages from DLT Users by
+fetching them from DLT Daemons. It may also issue control messages to control
+the behaviour of a DLT Daemon or its connected DLT Users. A DLT client can even
+transmit user-defined data to a DLT User through so-calles injection messages.
+
+This is only the simplest of all use cases that you will further pursue in the
+[Get Started](#get-started) section. Once you want to [learn more](#learn-more),
+you will find that the repository contains advanced features utilizing several
+adaptors and console utilities as well as test applications.
+
+## Get Started
+In this section, you can learn how to [build and install](#build-and-install)
+DLT. Then you can choose to [run a DLT demo](#run-a-dlt-demo) setup or to start
+by [developing your own DLT-featured application](#develop-your-own-dlt-featured-application).
+
+### Build and install
 
 The following packages need to be installed in order to be able to build and
 install DLT daemon:
@@ -36,114 +65,46 @@ install DLT daemon:
 
 On Ubuntu those dependencies can be installed with the following command:
 
-`sudo apt-get install cmake zlib1g-dev libdbus-glib-1-dev`
+```
+sudo apt-get install cmake zlib1g-dev libdbus-glib-1-dev
+```
+
+Then proceed to download DLT if you haven't already. We recommend cloning the
+repository, but downloading and extracting a zip-archive is fine as well.
+```bash
+cd /path/to/workspace
+git clone https://github.com/GENIVI/dlt-daemon.git
+```
 
 To build and install the DLT daemon, follow these steps:
 
 ```bash
+cd /path/to/workspace/dlt-daemon
 mkdir build
 cd build
 cmake ..
 make
 optional: sudo make install
-optional: sudo ldconfig
-```
-
-### Configuration
-
-#### General Options
-
-Option | Value | Comment
-:--- | :--- | :---
-BUILD\_SHARED\_LIBS | ON | Set to OFF to build static libraries
-DLT\_IPC                          |"FIFO"          | Set to either "UNIX\_SOCKET" or "FIFO"
-WITH\_DLT\_USE\_IPv6              | ON             | Set to ON for IPv6 support
-WITH\_DLT\_EXAMPLES               | ON             | Set to ON to build src/examples binaries
-DLT\_USER                         | genivi         | Set user for process not run as root
-WITH\_CHECK\_CONFIG\_FILE         | OFF            | Set to ON to create a configure file of CheckIncludeFiles and CheckFunctionExists
-CMAKE\_INSTALL\_PREFIX            | /usr/local
-CMAKE\_BUILD\_TYPE                | RelWithDebInfo
-WITH\_UDP\_CONNECTION             | ON             | Set to ON to enable dlt UDP multicast SUPPORT
-WITH\_DLT\_DAEMON\_VSOCK\_IPC     | OFF            | Set to ON for VSOCK support in daemon.
-WITH\_DLT\_LIB\_VSOCK\_IPC        | OFF            | Set to ON for VSOCK support in libdlt (DLT_IPC is overridden in libdlt).
-DLT\_VSOCK\_PORT                  | 13490          | Port to use for VSOCK communication.
-
-#### Command Line Tool Options
-
- Option | Value | Comment
- :--- | :--- | :---
-WITH\_DLT\_ADAPTOR                | OFF            | Set to ON to build src/adaptor binaries
-WITH\_DLT\_CONSOLE                | ON             | Set to ON to build src/console binaries
-WITH\_DLT\_SYSTEM                 | OFF            | Set to ON to build src/system binaries
-WITH\_DLT\_LOGSTORAGE\_CTRL\_UDEV | OFF            | PROTOTYPE! Set to ON to build
-WITH\_DLT\_KPI                    | OFF            | Set to ON to build src/kpi binaries
-
-#### Linux OS Integration Options
-
- Option | Value | Comment
- :--- | :--- | :---
-WITH\_SYSTEMD                     | OFF            | Set to ON to run CMakeLists.txt in systemd
-WITH\_SYSTEMD\_WATCHDOG           | OFF            | Set to ON to use the systemd watchdog in dlt-daemon
-WITH\_SYSTEMD\_JOURNAL            | OFF            | Set to ON to use the systemd journal in dlt-system
-WITH\_DLT\_DBUS                   | OFF            | Set to ON to build src/dbus binaries
-
-#### Documentation Options
-
-Option | Value | Comment
- :--- | :--- | :---
-WITH\_DOC                         | OFF            | Set to ON to build documentation target
-WITH\_MAN                         | OFF            | Set to OFF to skip building of man pages
-
-#### Test Options
-
-Option | Value | Comment
-:--- | :--- | :---
-WITH\_TESTSCRIPTS                 | OFF            | Set to ON to run CMakeLists.txt in test scripts
-WITH\_DLT\_TESTS                  | ON             | Set to ON to build src/test binaries
-WITH\_DLTTEST                     | OFF            | Set to ON to build with modifications to test User-Daemon communication with corrupt messages
-WITH\_DLT\_UNIT\_TESTS            | OFF            | Set to ON to build unit test binaries
-WITH\_GPROF                       | OFF            | Set \-pg to compile flag
-
-#### Experimental Features Options
-
-Option | Value | Comment
-:--- | :--- | :---
-WITH\_DLT\_SHM\_ENABLE            | OFF            | Set to OFF to use FIFO as IPC from user to daemon
-WITH\_DLT\_CXX11\_EXT             | OFF            | Set to ON to build C++11 extensions
-WITH\_DLT\_COREDUMPHANDLER        | OFF            | EXPERIMENTAL! Set to ON to build src/core\_dump\_handler binaries. EXPERIMENTAL
-
-In order to change these options, you can modify these values with cmake, do the
-appropriate changes in CmakeList.txt or via the commandline for cmake
-
-Change a value with: cmake -D\<Variable\>=\<Value\>, E.g.
-
-```bash
-cmake .. -DWITH_SYSTEMD=ON -DWITH_SYSTEMD_JOURNAL=ON -DCMAKE_INSTALL_PREFIX=/usr
+optional: sudo ldconfig # in case you executed make install
 ```
+CMake accepts a plethora of [build options](doc/dlt_build_options.md) to
+configure the build to suit your needs.
 
-## Documentation
+### Run a DLT demo
+In case you haven't had a look at the brief [overview](#overview), now would be
+the perfect occasion to learn about the most important terms and to get an idea
+where data is buffered. Then go on with our guide on [how to set up a DLT demo
+setup](doc/dlt_demo_setup.md).
 
-Specific documentation can be found in the following files:
+### Develop your own DLT-featured application
 
-- [ReleaseNotes](ReleaseNotes.md)
-- [Glossary](doc/dlt_glossary.md)
-- [For Developers](doc/dlt_for_developers.md)
-- [Logstorage](doc/dlt_offline_logstorage.md)
-- [MultiNode](doc/dlt_multinode.md)
-- [Extended Network Trace](doc/dlt_extended_network_trace.md)
-- [DLT Filetransfer](doc/dlt_filetransfer.md)
-- [DLT KPI](doc/dlt_kpi.md)
-- [DLT Core Dump Handler](/doc/dlt_cdh.md)
+Now that you have seen DLT in action, you probably want to develop your own
+applications using DLT. You will find everything you need in our ["DLT for
+Application Developers" guide](doc/dlt_for_developers.md).
 
-All text based documentation will be replaced with by Markdown-based documentation for convinient access.
-
-Old documentation (not maintained - will be removed in future releases):
-
-- DLT Design Specification: doc/dlt\_design\_specification.txt
-
-### API Documentation
-
-The API documentation is generated with _doxygen_.
+A hint: If you want to read the API documentation, you have to build it locally
+at the moment. The API documentation is generated with _doxygen_. To build it,
+run cmake with the ```-DWITH_DOC=ON``` option, e.g.:
 
 ```bash
 mkdir build
@@ -152,27 +113,39 @@ cmake -DWITH_DOC=ON ..
 make doc
 ```
 
-### Manpages
-
-- [dlt-daemon(1)](doc/dlt-daemon.1.md)
-- [dlt.conf(5)](doc/dlt.conf.5.md)
-- [dlt-system(1)](doc/dlt-system.1.md)
-- [dlt-system.conf(5)](doc/dlt-system.conf.5.md)
-- [dlt_gateway.conf(5)](doc/dlt_gateway.conf.5.md)
-- [dlt-convert(1)](doc/dlt-convert.1.md)
-- [dlt-sortbytimestamp(1)](doc/dlt-sortbytimestamp.1.md)
-- [dlt-receive(1)](doc/dlt-receive.1.md)
-- [dlt-control(1)](doc/dlt-control.1.md)
-- [dlt-logstorage-ctrl(1)](doc/dlt-logstorage-ctrl.1.md)
-- [dlt-passive-node-ctrl(1)](doc/dlt-passive-node-ctrl.1.md)
-- [dlt-adaptor-stdin(1)](doc/dlt-adaptor-stdin.1.md)
-- [dlt-adaptor-udp(1)](doc/dlt-adaptor-udp.1.md)
-- [dlt-qnx-system(1)](doc/dlt-qnx-system.md)
+## Learn more
+Once you got your feet wet with developing your first application, you might
+want to learn more. Find out about DLT's [advanced topics](#advanced-topics),
+learn how to [configure, control and interface](#configure-control-and-interface)
+DLT or study its internals by checking out the [design
+specifications](#design-specifications).
+
+### Advanced Topics
+The GENIVI DLT implementation is capable of by far more than to "just" send log
+message. You will get an overview of advanced features in this section. Follow
+the links to learn more about the respective concept.
+
+| Document | Description |
+|----|----|
+| [Build Options](./doc/dlt_build_options.md) | The CMake build system provides a large amount of build options. They let you turn on or off certain features and provide alternative implementation details. |
+| [LogStorage](doc/dlt_offline_logstorage.md) | The DLT Daemon as well as the DLT libary provide buffers for caching log data during absence of a consumer. However, some use cases require to write large amounts of log message e.g. to mass storages for long term storage or because no other means of exfiltrating the log data is available. |
+| [MultiNode](doc/dlt_multinode.md) | A DLT Daemon can run as a gateway to connect multiple passive nodes. Each passive node has its owns DLT Applications and runs its own daemon. The gateway node connects to all of them, collects the logs and routes them to the DLT Client. |
+| [Extended Network Trace](doc/dlt_extended_network_trace.md) | Normal DLT messages are limited in size. To overcome this limitation the feature network trace message allows the user to send or truncate messages which would not fit into a normal DLT message. |
+| [DLT Filetransfer](doc/dlt_filetransfer.md) | Although not originally designed for this, files can be transmitted over DLT. A corresponding DLT Client (e.g. DLT Viewer) can receive and decode them accordingly. |
+| [DLT KPI](doc/dlt_kpi.md) | Valueable status information about the monitored system can be read via DLT as well. The information under `/proc` of the target system is at your hands easily. |
+| [DLT Core Dump Handler](/doc/dlt_cdh.md) | This tool collects and extracts debug information then utilize [DLT Filetransfer](doc/dlt_filetransfer.md) to transfer the information to client. |
+
+### Configure, Control and Interface
+
+There is still lots to discover about DLT. If you turn on the generation of
+manpages with the cmake option ```-DWITH_MAN=ON``` you can learn how to
+configure DLT to exactly suit your needs, how to control the behvaiour of
+running instances and how to interface DLT with existing system through
+provided adaptors.
 
 The man pages are generated with *pandoc*.
 
-If the man pages are changed the following command must be executed.
-
+Build manpages (initally or because something changed) with e.g.
 ```bash
 mkdir build
 cd build
@@ -180,7 +153,24 @@ cmake -DWITH_MAN=ON ..
 make generate_man
 ```
 
-The generated man pages overwrite the existing ones.
+| Document | Description |
+|----|----|
+| *Configuration* ||
+|[dlt-daemon(1)](doc/dlt-daemon.1.md) | How to start DLT-Daemon |
+|[dlt.conf(5)](doc/dlt.conf.5.md) | Configure the DLT framework to reflect your use case|
+| *Control running instances of DLT*||
+|[dlt-receive(1)](doc/dlt-receive.1.md)| Receive DLT messages from daemon and print or store the log messages. |
+|[dlt-control(1)](doc/dlt-control.1.md)| Send control messages to daemon. |
+|[dlt-logstorage-ctrl(1)](doc/dlt-logstorage-ctrl.1.md)| Send a trigger to daemon to connect/disconnect certain logstorage device, or send a demand to sync data the internal buffer into logstorage file. |
+|[dlt-passive-node-ctrl(1)](doc/dlt-passive-node-ctrl.1.md)| Send a trigger to daemon to connect/disconnect passive daemon. |
+| *Interfacing DLT* ||
+|[dlt-system(1)](doc/dlt-system.1.md) | DLT-System provides a way to directly access system logs via DLT |
+|[dlt-system.conf(5)](doc/dlt-system.conf.5.md) | Configure DLT-System |
+|[dlt-adaptor-stdin(1)](doc/dlt-adaptor-stdin.1.md)| Adaptor for forwarding input from stdin to daemon. |
+|[dlt-adaptor-udp(1)](doc/dlt-adaptor-udp.1.md)| Adaptor for forwarding received UDP messages to daemon. |
+|[dlt-convert(1)](doc/dlt-convert.1.md)| Convert DLT files into human readable format. |
+|[dlt-sortbytimestamp(1)](doc/dlt-sortbytimestamp.1.md)| Read log messages from DLT file, sort by timestamp, and store them again. |
+| [dlt-qnx-system(1)](doc/dlt-qnx-system.md) | Access system logs in QNX with DLT |
 
 ## Contribution
 
@@ -188,7 +178,9 @@ Start working, best practice is to commit smaller, compilable pieces during the
 work that makes it easier to handle later on.
 
 If you want to commit your changes, create a
-[Pull Request](https://github.com/genivi/dlt-daemon/pulls) in Github.
+[Pull Request](https://github.com/genivi/dlt-daemon/pulls) in Github. Please
+make sure to follow the
+[Rules for commit messages](https://at.projects.genivi.org/wiki/display/PROJ/Rules+for+Commit+Messages)
 
 ### Coding Rules
 
diff --git a/doc/dlt_build_options.md b/doc/dlt_build_options.md
new file mode 100644
index 0000000..9a91193
--- /dev/null
+++ b/doc/dlt_build_options.md
@@ -0,0 +1,81 @@
+# DLT Build Options
+
+DLT is highly configurable. It allows you to choose between certain technologies
+or implementations and to turn on or off certain features. This way, you can
+adjust it to your needs and keep the build process as simple as possible.
+
+In order to change these options, you can modify these values with cmake, do the
+appropriate changes in CmakeList.txt or via the commandline for cmake
+
+Change a value with: cmake -D\<Variable\>=\<Value\>, E.g.
+
+```bash
+cmake .. -DWITH_SYSTEMD=ON -DWITH_SYSTEMD_JOURNAL=ON -DCMAKE_INSTALL_PREFIX=/usr
+```
+
+## General Options
+
+Option | Value | Comment
+:--- | :--- | :---
+BUILD\_SHARED\_LIBS | ON | Set to OFF to build static libraries
+DLT\_IPC                          |"FIFO"          | Set to either "UNIX\_SOCKET" or "FIFO"
+WITH\_DLT\_USE\_IPv6              | ON             | Set to ON for IPv6 support
+WITH\_DLT\_EXAMPLES               | ON             | Set to ON to build src/examples binaries
+DLT\_USER                         | genivi         | Set user for process not run as root
+WITH\_CHECK\_CONFIG\_FILE         | OFF            | Set to ON to create a configure file of CheckIncludeFiles and CheckFunctionExists
+CMAKE\_INSTALL\_PREFIX            | /usr/local
+CMAKE\_BUILD\_TYPE                | RelWithDebInfo
+WITH\_UDP\_CONNECTION             | OFF            | Set to ON to enable dlt UDP multicast SUPPORT
+WITH\_DLT\_DAEMON\_VSOCK\_IPC     | OFF            | Set to ON for VSOCK support in daemon.
+WITH\_DLT\_LIB\_VSOCK\_IPC        | OFF            | Set to ON for VSOCK support in libdlt (DLT\_IPC is overridden in libdlt).
+DLT\_VSOCK\_PORT                  | 13490          | Port to use for VSOCK communication.
+
+## Command Line Tool Options
+
+ Option | Value | Comment
+ :--- | :--- | :---
+WITH\_DLT\_ADAPTOR                | OFF            | Set to ON to build src/adaptor binaries
+WITH\_DLT\_CONSOLE                | ON             | Set to ON to build src/console binaries
+WITH\_DLT\_SYSTEM                 | OFF            | Set to ON to build src/system binaries
+WITH\_DLT\_LOGSTORAGE\_CTRL\_UDEV | OFF            | PROTOTYPE! Set to ON to build
+WITH\_DLT\_KPI                    | OFF            | Set to ON to build src/kpi binaries
+
+## Linux OS Integration Options
+
+ Option | Value | Comment
+ :--- | :--- | :---
+WITH\_SYSTEMD                     | OFF            | Set to ON to run CMakeLists.txt in systemd
+WITH\_SYSTEMD\_WATCHDOG           | OFF            | Set to ON to use the systemd watchdog in dlt-daemon
+WITH\_SYSTEMD\_JOURNAL            | OFF            | Set to ON to use the systemd journal in dlt-system
+WITH\_DLT\_DBUS                   | OFF            | Set to ON to build src/dbus binaries
+
+## QNX OS Integration Options
+
+Option | Value | Comment
+:--- | :--- | :---
+WITH\_DLT\_QNX\_SYSTEM            | OFF            | Set to ON to build QNX system binary dlt-qnx-system
+
+## Documentation Options
+
+Option | Value | Comment
+ :--- | :--- | :---
+WITH\_DOC                         | OFF            | Set to ON to build API documentation
+WITH\_MAN                         | OFF            | Set to ON to build man pages
+
+## Test Options
+
+Option | Value | Comment
+:--- | :--- | :---
+WITH\_TESTSCRIPTS                 | OFF            | Set to ON to run CMakeLists.txt in test scripts
+WITH\_DLT\_TESTS                  | ON             | Set to ON to build src/test binaries
+WITH\_DLTTEST                     | OFF            | Set to ON to build with modifications to test User-Daemon communication with corrupt messages
+WITH\_DLT\_UNIT\_TESTS            | OFF            | Set to ON to build unit test binaries
+WITH\_GPROF                       | OFF            | Set \-pg to compile flag
+
+## Experimental Features Options (Dragons ahead!)
+
+Option | Value | Comment
+:--- | :--- | :---
+WITH\_DLT\_SHM\_ENABLE            | OFF            | Set to ON to enable shared memory as IPC
+WITH\_DLT\_CXX11\_EXT             | OFF            | Set to ON to build C++11 extensions
+WITH\_DLT\_COREDUMPHANDLER        | OFF            | Set to ON to build src/core\_dump\_handler binaries.
diff --git a/doc/dlt_demo_setup.md b/doc/dlt_demo_setup.md
new file mode 100644
index 0000000..3d357f4
--- /dev/null
+++ b/doc/dlt_demo_setup.md
@@ -0,0 +1,88 @@
+# DLT Demo Setup
+Back to [README.md](../README.md)
+
+In this document you will run an instance of
+dlt-daemon. It silently waits to collect and buffer log messages that are
+produced by one or multiple DLT users. You will run one of those DLT users and
+make it produce log messages that are sent to the daemon. Eventually, you launch
+a client that collects and displays these messages.
+
+*Note: We assume that you installed DLT (i.e. executed the [two optional steps
+after build](../README.md#build-and-install)). Otherwise you have to take care
+of the executable paths and explicitly state the library path.*
+
+## Run the DLT Daemon
+The DLT daemon is highly configurable but for this case the default settings are
+okay. Don't be put off by warning messages:
+```bash
+$ dlt-daemon
+[1886222.668006]~DLT~32290~NOTICE   ~Starting DLT Daemon; DLT Package Version: 2.18.0 STABLE, Package Revision: v2.18.1, build on Dec  8 2020 11:11:51
+-SYSTEMD -SYSTEMD_WATCHDOG -TEST -SHM
+
+[1886222.668651]~DLT~32290~INFO     ~FIFO size: 65536
+[1886222.668764]~DLT~32290~INFO     ~Activate connection type: 5
+[1886222.668897]~DLT~32290~INFO     ~dlt_daemon_socket_open: Socket created
+[1886222.669047]~DLT~32290~INFO     ~dlt_daemon_socket_open: Listening on ip 0.0.0.0 and port: 3490
+[1886222.669159]~DLT~32290~INFO     ~dlt_daemon_socket_open: Socket send queue size: 16384
+[1886222.669355]~DLT~32290~INFO     ~Activate connection type: 1
+[1886222.669509]~DLT~32290~INFO     ~Activate connection type: 9
+[1886222.669644]~DLT~32290~INFO     ~Ringbuffer configuration: 500000/10000000/500000
+[1886222.669924]~DLT~32290~NOTICE   ~Failed to open ECU Software version file.
+[1886222.670034]~DLT~32290~INFO     ~Activate connection type: 6
+[1886222.670188]~DLT~32290~INFO     ~Switched to buffer state for socket connections.
+[1886222.670365]~DLT~32290~WARNING  ~dlt_daemon_applications_load: cannot open file /tmp/dlt-runtime-application.cfg: No such file or directory
+```
+The daemon opened a named pipe from which it is ready to read and buffer log
+messages. It also accepts connections on TCP port 3490 by clients to collect
+the messages.
+
+## Produce Log Messages
+A simulated ECU - a DLT user - will now use the DLT library to create log
+messages and send them through the named pipe for the daemon to collect. Open a
+second terminal and run
+```bash
+$ dlt-example-user -n 5 -l 3 "This is my first log message"
+Send 0 This is my first log message
+Log level changed of context TEST, LogLevel=4, TraceState=0
+Log level changed of context TS1, LogLevel=4, TraceState=0
+Log level changed of context TS2, LogLevel=4, TraceState=0
+Send 1 This is my first log message
+Client disconnected!
+Send 2 This is my first log message
+Send 3 This is my first log message
+Send 4 This is my first log message
+```
+This will send 5 (```-n 5```) identical log messages of Log-Level
+WARNING ```(-l 3)``` containing a string payload.
+
+## Read logs
+The DLT daemon now has the messages in its buffer and will keep them there until
+they are fetched. A mighty tool for receiving and processing log messages is the
+[DLT-Viewer](https://github.com/GENIVI/dlt-viewer), which also provides a
+graphical UI. For now, a simple command line client is absolutely sufficient:
+```bash
+$ dlt-receive -a localhost
+2020/04/30 12:27:14.976731   17134987 000 ECU1 DA1- DC1- control response N 1 [service(3842), ok, 02 00 00 00 00]
+2020/04/30 12:27:14.976779   17067139 000 ECU1 DA1- DC1- control response N 1 [service(3842), ok, 01 00 00 00 00]
+2020/04/30 12:27:14.976787   17067139 004 ECU1 DLTD INTM log info V 1 [Client connection #7 closed. Total Clients : 0]
+2020/04/30 12:27:14.976794   17104625 005 ECU1 DLTD INTM log info V 1 [ApplicationID 'LOG' registered for PID 5241, Description=Test Application for Logging]
+2020/04/30 12:27:14.976802   17104625 000 ECU1 DA1- DC1- control response N 1 [get_log_info, 07, 01 00 4c 4f 47 00 01 00 54 45 53 54 ff ff 18 00 54 65 73 74 20 43 6f 6e 74 65 78 74 20 66 6f 72 20 4c 6f 67 67 69 6e 67 1c 00 54 65 73 74 20 41 70 70 6c 69 63 61 74 69 6f 6e 20 66 6f 72 20 4c 6f 67 67 69 6e 67 72 65 6d 6f]
+2020/04/30 12:27:14.976823   17104625 000 ECU1 DA1- DC1- control response N 1 [get_log_info, 07, 01 00 4c 4f 47 00 01 00 54 53 31 00 ff ff 1b 00 54 65 73 74 20 43 6f 6e 74 65 78 74 31 20 66 6f 72 20 69 6e 6a 65 63 74 69 6f 6e 1c 00 54 65 73 74 20 41 70 70 6c 69 63 61 74 69 6f 6e 20 66 6f 72 20 4c 6f 67 67 69 6e 67 72 65 6d 6f]
+2020/04/30 12:27:14.976844   17104625 000 ECU1 DA1- DC1- control response N 1 [get_log_info, 07, 01 00 4c 4f 47 00 01 00 54 53 32 00 ff ff 1b 00 54 65 73 74 20 43 6f 6e 74 65 78 74 32 20 66 6f 72 20 69 6e 6a 65 63 74 69 6f 6e 1c 00 54 65 73 74 20 41 70 70 6c 69 63 61 74 69 6f 6e 20 66 6f 72 20 4c 6f 67 67 69 6e 67 72 65 6d 6f]
+2020/04/30 12:27:14.976866   17104588 000 ECU1 LOG- TEST log warn V 2 [0 This is my first log message]
+2020/04/30 12:27:14.976872   17109592 001 ECU1 LOG- TEST log warn V 2 [1 This is my first log message]
+2020/04/30 12:27:14.976880   17114599 002 ECU1 LOG- TEST log warn V 2 [2 This is my first log message]
+2020/04/30 12:27:14.976884   17119607 003 ECU1 LOG- TEST log warn V 2 [3 This is my first log message]
+2020/04/30 12:27:14.976889   17124611 004 ECU1 LOG- TEST log warn V 2 [4 This is my first log message]
+2020/04/30 12:27:14.976894   17134988 006 ECU1 DLTD INTM log info V 1 [New client connection #8 established, Total Clients : 1]
+2020/04/30 12:27:15.442016   17139641 000 ECU1 DA1- DC1- control response N 1 [service(3841), ok, 4c 4f 47 00 54 45 53 54 72 65 6d 6f]
+2020/04/30 12:27:15.442044   17139642 007 ECU1 DLTD INTM log info V 1 [Unregistered ApID 'LOG']
+```
+The client connects to the default port 3490 of localhost to collect all
+messages and interprets the payload as ASCII text (```-a```). You can see lots
+of additional messages. These are control messages to control the flow between
+client and daemon. You will learn about them later. For now, you have set up a
+basic example have seen DLT in action.
+
+You can now experiment with this setup. What happens if you start the DLT user
+first and (while the DLT user is still running) the daemon?
\ No newline at end of file
diff --git a/doc/dlt_glossary.md b/doc/dlt_glossary.md
index 06f0cb9..843b9ab 100644
--- a/doc/dlt_glossary.md
+++ b/doc/dlt_glossary.md
@@ -10,6 +10,8 @@ Application ID | Application Identifier is a unique identifier for an applicatio
 Context ID	| This is a user defined ID to group log and trace messages produced by an application. Each Application ID can own several Context IDs and the Context IDs shall be unique within an Application ID. The identification of the source of a log and trace message is done with a pair of Application ID and Context ID. It is composed by four 8 bit ASCII characters.
 Control Message	| A control message is send by a connected client application (e.g. Log Viewer) to the DLT Daemon that includes an action request. E.g. change the Log level of a certain application).
 DLT Daemon | The DLT Daemon is the central component which receives all logs and traces from the DLT user applications. The DLT Daemon forwards all logs and traces to a connected DLT client (e.g. Log Viewer) or stores them optionally in a file on the target.
+DLT Library | Provides applications (esp. DLT users) with an API to produce DLT messages and to handle DLT Control Messages accordingly.
+DLT User | A DLT User is a type of application that produces log messages. It typically uses the DLT library to produce the messages and resembles an ECU.
 DLT Viewer | The DLT Viewer is the GENIVI Log Viewer implementation. It is a Qt-based desktop application able to run on Windows and Linux operating systems. Further information and source code can be found here: https://github.com/GENIVI/dlt-viewer
 Gateway DLT Daemon | In a Multi-Node system, the DLT Daemon running on the Node directly connected to a Log Viewer is called Gateway DLT Daemon (if configured as Gateway). It forwards log messages from Passive DLT Daemons to Log Viewers and command/control messages from Log Viewer(s) to Passive DLT Daemon(s).
 Injection Message | An injection message is a control message for a specific DLT application.