If more than 7 Bytes of data in a single frame in UDS(Unified Diagnostic Services)?

[PRATIK.PATI]

In UDS a maximum of & bytes can be sent. If the length exceeds then how its managed?

Example:

In SID2E, the frame is-

07 -> 2E-> did1-> did2-> data1-> data2-> data3-> data4->

if there are more data bytes present then what will happen?
Who will handle it(the protocol or the user)?
And how its handled?

 

[BradtheRad]

A number stored as a binary is assigned 1 or 2 or 4 bytes. The communication protocol sends as many bytes as were assigned to the number. When writing your own communication program you need to command a 'send' with the correct syntax. The receiving unit must have its receive command written in the correct syntax. An incoming number must have a correct amount of bytes assigned. Variables need to be sent and received in proper sequence.

Sometimes it is easier to send a number as a string. Strings are less fussy. And a number converted to a string in base 10 occupies fewer bytes than the same number in binary.

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You may decide it's practical to concatenate several such base 10 strings (separated by a space), thus sending several numbers in one string.

It's easy for humans to look at the incoming string displayed in base 10 on the receiving unit, and recognize whether all the data was sent and received.

 

[PRATIK.PATI]

How the service id 3D(WriteMemoryByAddress) is used(UDS)?

When the WriteMemoryByAddress is used ?