.. include:: ../../../../macros.txt
.. include:: ../../../../units.txt

.. _HOW_TO_TEST_TCP_IP:

How to Test TCP/IP
===================

.. warning::

   In Hardware version 1.2.3 and below, the PHY is enabled by default,
   which can cause issues when connecting the Ethernet cable.
   To avoid this, the pull-up resistors enabling the PHY should be removed.
   For more details, refer to :ref:`REMOVING_THE_PULL_UP_RESISTOR_FOR_THE_PHY`.

Most of the configuration is already done in the |foxbms| implementation.
If changes in the |freertos| port for |tcp-ip| are necessary, refer to
:ref:`HOW_TO_IMPLEMENT_ETHERNET_PORT`.
To use |tcp-ip|, configure it as described in :ref:`CONFIGURE_OS`.

To connect the |bms-master| with the Ethernet cable, refer to
:ref:`TI_TMS570_BASED_BMS_MASTER_V1_2_2_PINOUT`.
After the physical connection is established, the CAN message ``f_BmsState``
sets ``PhyLinked`` to ``1``.
Now |foxbms| can be pinged or the echo server can be used.

.. hint::

   It can be usefull to deactivate during testing other network connections as
   WiFi.

Debug the Network connection
-----------------------------

For debugging purposed the UART interface can be used.
The general configuration is described in :ref:`CONFIGURE_DEBUG`.

How to Ping |foxbms|
---------------------

This section shows how to send a simple ping message to |foxbms|.
In ``FreeRTOSIPConfig.h`` ``ipconfigREPLY_TO_INCOMING_PINGS`` is enabled.
This is why the |tcp-ip-stack| answers ping messages by default without a
server being initialized.
To enable |foxbms| to respond to ping, some application code is
provided in ``src/app/application/ethernet/ethernet.c``.

The interface descriptor is initialized with
``pxTMS570_FillInterfaceDescriptor``.
The IP address and other network parameters have to be set with
``FreeRTOS_FillEndPoint``.
To initialize the |tcp-ip-stack|, ``FreeRTOS_IPInit_Multi`` is called.
The tasks that use the network are created in the
``vApplicationIPNetworkEventHook`` hook function.
This hook function is called when the network connects.

Using Ping
^^^^^^^^^^^^

Ping is a standard program for checking an ethernet connection.
The default IP Address is **169.254.107.24**.
DHCP is currently not used, so static addresses need to be assigned.
All of the related configuration can be found in
``src/app/application/config/ethernet_cfg.c``.

When calling ``ping <ip address>`` it should return

.. code-block:: powershell

   PS > ping 169.254.107.24
   Pinging 169.254.107.24 with 32 bytes of data:
   Reply from 169.254.107.24: bytes=32 time<1ms TTL=255
   Reply from 169.254.107.24: bytes=32 time=1ms TTL=255
   Reply from 169.254.107.24: bytes=32 time=1ms TTL=255
   Reply from 169.254.107.24: bytes=32 time<1ms TTL=225

   Ping statistics for 169.254.107.24:
   Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
   Approximate round trip times in milli-seconds:
   Minimum = 0ms, Maximum = 1ms, Average = 0ms

With the parameter ``-n`` it is possible to choose the number of requests.

How to Test the Echo Sever
---------------------------

For testing the echo server the program Putty is used.
The default IP Address is **169.254.107.24** and the echo server port is **7**.
It has to be configured as follows:

Putty configuration:
``Session:Host Name:<foxBMS IP Address>``
``Session:Port:<foxBMS Echo Server Port>``
``Session:Connection Type:raw``

For better readability:
``Terminal:Implicit CR in every LF``
``Terminal:Implicit LF in every CR``

When establishing the connection it should output

.. code-block:: powershell

   Connected to client
   Started connection instance

With the tool Wireshark the TCP handshake can be observed.
It should look like in the image below.

.. figure:: img/tcp-handshake.png
   :alt: Log of TCP handshake
   :name: tcp-handshake
   :width: 100 %

   TCP-handshake

Now every input to the Putty terminal is echoed back.
The image below illustrates the data send.

.. figure:: img/tcp-response.png
   :alt: Log of TCP echo response
   :name: tcp-response
   :width: 100 %

   Log showing the TCP echo request and response

On closing the TCP connection another handshake is performed as shown in
:numref:`tcp-close`.

.. figure:: img/tcp-close.png
   :alt: Protocol of TCP handshake
   :name: tcp-close
   :width: 100 %

   Log showing the closing procedure of a TCP connection

See Also
--------

- :ref:`PHY_MODULE`
- :ref:`NETWORK_INTERFACE`
- :ref:`EMAC`
- :ref:`HOW_TO_IMPLEMENT_ETHERNET_PORT`
- :ref:`ETHERNET_MODULE`