Practical Wiring - Professional Motorsport: Network Design
Network Design
02.37
00:00 | - Modern motorsport electrical systems will almost always include one or more network communication buses. |
00:06 | Either for the transmission of data between parts of the system or programming of the various ECUs present in the vehicle. |
00:13 | For the transmission of data between devices, CAN bus is the most common network used. |
00:19 | And the wiring requirements are covered in our wiring fundamentals course. |
00:23 | These requirements don't vary at the motorsport level but if the network bus does need to run alongside electrically noisy wires, or close to ignition components, the use of shielded cable is a good way to add a factor of safety. |
00:38 | Ethernet is another network bus that you will strike when wiring automotive electronics aimed at the motorsport level. |
00:44 | It is the same networking protocol used by the computer industry however we usually stray slightly from the standards to make our bus wiring more suitable in an automotive environment. |
00:55 | An ethernet bus consists of four wires, transmit positive and negative, and receive positive and negative. |
01:02 | Because the bus transmits and receives on different pairs of wires, it's what's known as full duplex. |
01:09 | Meaning it can both receive data and transmit data at the same time. |
01:14 | The networking standards employed by computers call for a cable to be used that has four twisted pairs of wires making eight total. |
01:22 | The extra four wires used are for higher speed data transmission and not often needed in an automotive installation so they are usually omitted. |
01:31 | To form an ethernet network of more than two devices, we need to use a network hub or switch. |
01:38 | This device monitors the traffic on the network and directs it where it needs to go. |
01:42 | This is a key point of difference to the CAN bus network where every device can see all the data on the bus. |
01:49 | In an ethernet network, data is sent in distinct packets that have a specific destination and will only end up at that destination. |
01:57 | Ethernet is more commonly used for ECU programming and configuration rather than data transmission between devices. |
02:05 | And for this reason, it's common to wire the ethernet pins of a device to an easily accessible connector in the vehicle. |
02:11 | So a connection to a laptop can be quickly made for programming. |
02:15 | I tend to collect up all the ethernet and CAN buses together into a single diagnosis and programming connector mounted on the main switch panel of the vehicle. |
02:25 | I then create a single programming cable that breaks the buses out to the required connectors for interfacing to a laptop or diagnostic equipment. |