Hi,

I'm quite new to canopen, and need to implement a device using IP mode. I now want to use objects 60C1 and 60C2 for position/time data.
The documentation says that the unit for 60C2 is "10 interpolation time index".
Where is " interpolation time index" defined, or in other words, how can I determine or specify the unit for 60C2?

 

Welcome to AAC.

As far as I can tell, the interpolation time index sets a coefficient that determines the unit. There is no unit for 60C2h 2h, it is just an 8 bit signed integer that determines the meaning of 60C2h 1h as parts of a second in milliseconds.

Since the time appears to be restricted to intervals of 62.5ms, 60C2h 2h and 1h will have to be set in such a way that the result is no smaller than the 1ms resolution limit and works for the 62.5ms resolutiojn.

 

Hi, I'm afraid I dont completely understand it.

Now the documentation says that 60C2h 2h has a possible range of -128 ..63, with a default value of -3.
Could you elaborate your answer using an example with, for example the default value of -3.

 

Hi, I'm afraid I dont completely understand it.

Now the documentation says that 60C2h 2h has a possible range of -128 ..63, with a default value of -3.
Could you elaborate your answer using an example with, for example the default value of -3.

\[ Sample\ Period\ \mathsf{\small{(seconds)}} = \\ {{ \it { Interpolation\ Time\ Period\ Value\ } } {\small{(8\ bit\ unsigned\ integer)}} \times\ 10^ \color{red}{ \it{ Interpolation\ Time\ Index } } {\small{(8\ bit\ signed\ integer)}} } \\ { \text{ so given a value of -3 for } } \mathsf{ 60C2\ 2h } { \text{ we have } } \\ \mathsf{ { \it{ Sample\ Period } }\ seconds = { \it { Interpolation\ Time\ Period\ Value } } \ \times\ \color{red}{10^-3} } \]
So now, whatever you set 60C2 2h to will represent that times 10 to the minus 3 seconds for the sample period.