Hi all, so as I generally have the properties: startIndex, endIndex and numElements I decided to add a third notation:
* XYZ[8] • ( elements from the start of the defined array (doesn’t matter where the start is) * XYZ[3..10] • (All Elements starting with index 3 and ending with index 10: 3, 4, 5, 6, 7, 8, 9 and 10) * XYZ[3:4] • (4 Elements starting with index 3: 3, 4, 5 and 6) I thought, as I have the properties anyway, might just as well provide different options to define what you’re looking for. Chris From: Ben Hutcheson <[email protected]> Date: Sunday, 30. October 2022 at 02:14 To: [email protected] <[email protected]> Subject: Re: Change the array-notation in fields? Yeah I'd be happy with that approach. Sounds good, I'll have to take a lot whether we can read random indices in OPC-UA. On Sat, Oct 29, 2022 at 3:35 PM Christofer Dutz <[email protected]> wrote: > Don’t know if you followed that discussion on LinkedIn, where I asked > about the array notation. > > Turned out that you can generally do all sorts of crazy stuff … such as > define Arrays that start at 6 and go to 12 … in general you can let your > first element be whatever you like. > > I guess if we interpret just one number as array size and if the array is > defined as [6..12] and I read a [3], then it should probably return the > elements 6,7,8 … but if I do a [0..3] it should probably fail and if I do > [7..10] then it should return 7, 8, 9 and 10. > > Would that interpretation make more sense? Then on PLCs where the first > element has the index 1 I can continue to use the same semantics as in one > where 0 is the default. However the user would have to know which is the > first index when using the X..Y notation. > > Chris > > > From: Christofer Dutz <[email protected]> > Date: Saturday, 29. October 2022 at 20:15 > To: [email protected] <[email protected]> > Subject: Re: Change the array-notation in fields? > Hi Ben, > > in general we currently have no option to read partial arrays starting > with anything else than the first element. > That’s generally what I’m currently trying to add. > > Chris > > From: Ben Hutcheson <[email protected]> > Date: Saturday, 29. October 2022 at 18:35 > To: [email protected] <[email protected]> > Subject: Re: Change the array-notation in fields? > As long as the original notation is kept, Im sure no one will mind. > Changing the wording in the original from numElements to endIndex seems to > have very little effect except to force the user to think about the start > index as starting at 1. > > In practise do we have the ability to read partial arrays in any of the > drivers? > > > > On Sat, 29 Oct 2022 at 9:35 am, Lukas Ott <[email protected]> wrote: > > > The question for me is why not startIndex = 0 > > Instead of 1. > > > > In general this proposal sound reasonable to me and a I opt +1. > > Luk > > > > Am Sa., 29. Okt. 2022 um 17:30 Uhr schrieb Christofer Dutz < > > [email protected]>: > > > > > Hi all > > > > > > currently in most drivers we support an array notation like: > > > XYZ{numElements}] > > > In order to support reading arrays. > > > > > > Now in order to support reading partial arrays, I think it would be > good > > > to generally change that to: > > > > > > XYZ[{startIndex}..{endIndex}] > > > > > > And the ordinary version: > > > > > > XYZ[{endIndex}] > > > > > > This would imply starting at the first element. > > > However, we should probably start with index “1”, as this seems to be > > what > > > most seem to use. > > > > > > So: > > > XYZ > > > Would be the same as: > > > XYZ[1] > > > Would be the same as: > > > XYZ[1..1] > > > > > > What do you think? > > > > > > Chris > > > > > >
