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A DAQ list consists of multiple ODTs which are "numbered".

Is it part of the XCP standard that the ODTs in a DAQ list must be transmitted in an ordered manner?

Bob
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1 Answers1

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From the section

1.3.4 XCP Packet Addressing for DAQ and STIM

of the XCP Reference Book available from Vector here, there are two ways of addressing packet with DAQ.

Absolute ODT numbers, which requires a transmission in an ordered manner
Relative ODT numbers, which doesn't.

Benoît
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  • `Absolute means that the ODT numbers are unique throughout the entire communication – i.e. across all DAQ lists.` so why would they need to be transmitted in any order? – Bob Jul 01 '19 at 14:37
  • `In turn, this means that the use of absolute ODT numbers assumes a transformation step that utilizes a so­called “FIRST_PID for the DAQ list.If a DAQ list starts with the PID j, then the PID of the first packet has the value j, the second packet has the PID value j + 1, the third packet has the PID value j + 2, etc. Naturally, the Slave must ensure here that the sum of FIRST_PID + relative ODT number remains below the PID of the next DAQ list.` Because you don't specify the relative part while transmitting: first to arrive is +1, second +2, ... – Benoît Jul 01 '19 at 15:53