Ing. Buero Dieter Munkes News   •   Sept 2, 2017

Actual communication in cars changes. We know LIN , CNA over the years, but now we are moving to BroadR-Reach.

Some words about:

• Developed to cover the last mile in connecting houses.
• 100Mbit over 2 twisted wires.
• classic TCP/IP with changed physical layer.
• Chipset is cheap and avaliable.

Sound fine , but what is the physical parameters for use in a car?

TPC/IP is pear to peer. There is no big switch in the middel of a car.

Every device has to have minimum 2 ports and a kind of switch. (chaining)

With this it can pick the interesting informations out of the stream and route the remaining.

Build test equipment

We got the order to build a tester with 6 simultaus devices running in climate-chamber.

They need to hold in sleep and life state, measure parameters and communicate to get errors and function tests.

BroadR-Reach can be done by media converter.

Fine so far, just one PC, one switch and 6 media converter…. we offered.

During setup we found:

• All devices have the same fixed IP adress and same MAC-adress.
• NO router in the world will handle this (or get real expensive)
• The device sends everthing with TTL=1 -> no one route this
• It uses for network keep alive multicast and for camera data broadcast.
• Data content was like CAN over TPC

How we got this done:

We took 12 Raspberry PI on boards with UPS in one row. Add additional NIC to them.

Write some services in python for moving and nating  data between the networks.

With this the PC see everything in a normal network. The PC see every device now in it´s own range.

Finally, everything was fine. But we learned again that automotive may be special.