RE: Re: CAN implementation extra

"John Dammeyer" <[email protected]>
Newsgroups gmane.comp.hardware.bus.can
Message-ID <[email protected]>
Thank you Heinz.
You've put your finger on exactly why so many people get confused.  You are
right.  No one sends an RPDO.  It's a naming convention to help with
allocating the data from a message to the object dictionary.  

The default TPDOx and RPDOx are perfect examples of this confusion.  Any
node waiting for an standard defined RPDO1 of 0x200+NodeID will never
receive it because the standard TPDOx are on the 0x180+NodeID increments and
no one sends an RPDO1.

From the CANOpen Wiki for example:
"There are two kinds of PDOs: transmit and receive PDOs (TPDO and RPDO). The
former is for data coming from the device and the latter is for data going
to the device; that is, with RPDO you can send data to the device and with
TPDO you can read data from the device. In the pre-defined connection set
there are identifiers for four (4) TPDOs and four (4) RPDOs available. With
configuration 512 PDOs are possible."

IMHO, it's assigning an ID to an RPDO that leads to confusion.  
John Dammeyer
 

> -----Original Message-----
> From: [email protected] [mailto:canlist-
> [email protected]] On Behalf Of Heinz-Jürgen Oertel
> Sent: January-09-15 3:04 PM
> To: CANLIST
> Subject: Re: [CANLIST] Re: CAN implementation extra
> 
> 
> Am Freitag, 9. Januar 2015, 08:59:18 schrieb John Dammeyer:
> > and who sends an RPDO.
> 
> no one has to send an RPDO.
> But one or more then one has to receive it. (one others TPDO).
> 
> --
> mit freundlichen Grüßen
>        Heinz-Jürgen Oertel
> --
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