Re: CANopen and the need for time-stamping

Am Donnerstag, 23. Oktober 2014, 13:30:04 schrieb Janakiraman, Hareesh:
> Hello,
>             Some CAN implementations have a built-in timer for time-stamping of messages. These timers also provide a time-out interrupt should transmission or reception of a mailbox does not occur in a pre-determined time. The eCAN module of in the 28xx MCUs from TI is an example. My question is this: Is the presence of a built-in timer absolutely essential for CANopen implementation? (Note that I am not referring to timers that are external to the CAN module, since all MCUs have one or more of “general-purpose” timers). I believe the answer is “no”, since I see in the websites of many 3rd parties who develop CANopen stacks a list of processors and I know not all of them have a built-in timer/counter as part of the CAN IP.
>  
> Hareesh Jana

Your guess is correct. Such a timer is not absolutely necessary. Most applications live without it. If needed the CANopen application can use a normal timer (and of course a piece of software) to monitor receive or transmit time-out conditions. But having a hardware support in the CAN controller is great.

-- 
mit freundlichen Grüßen
       Heinz-Jürgen Oertel
	emtas GmbH

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