V50 T5 AWD L5-2.5L Turbo VIN 67 B5254T7 (2008)
synchronous data and which are receivers.
Asynchronous data
Asynchronous data is used to send large quantities of data, such as TCP/IP and digital images, but not in real time.
The length of the message can be up to 36 bytes (synchronous data minimum 24 bytes + asynchronous data 36 bytes = 60 bytes). This gives a maximum
transfer rate of 14 Mbits per second. When the message has been sent, a check is run to ensure that is has been correctly received.
Asynchronous data shares the data frame with synchronous data. The infotainment control module (ICM) controls which control modules transmit
asynchronous data and which are receivers.
Administrative data
Administrative data consists of two parts.
The first part is at the start of the data frame. This describes how much of the transmitted data is synchronous and how much is asynchronous.
The second part is at the end of the data frame. This part checks that the control modules on the MOST network are working correctly.
The size of administrative data is 2 bytes.
MOST data frame
A data frame consists of different parts. This contains for example:
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control data
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asynchronous data
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synchronous data and
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administrative data.
A data frame on the MOST network is 64 bytes. The data frame consists of the following:
1. synchronization of the clock on the MOST network, i.e. the frequency at which data is transmitted so that the data is sent at the correct intervals
2. administrative data, indicates the size of the asynchronous and synchronous data
3. synchronous data
4. asynchronous data
5. control data
6. administrative data.
16 data frames are required to form a block. One block is the minimum size of a MOST message.
MOST protocol
