Re: BOOLeans ;-)

[jl hong <my...@gmail.com>]

Thank you, Chris :)

Christofer Dutz <ch...@c-ware.de> 於 2022年11月1日 週二 凌晨12:09寫道：

> I Ji,
>
> First of all: welcome to the team as our newest committer :-)
>
> I guess I really should start writing stuff like this up … then we can
> discuss things here and once we’ve agreed on it, make sure we use the same
> interpretation all over PLC4X.
>
> Chris
>
> From: jl hong <my...@gmail.com>
> Date: Monday, 31. October 2022 at 02:25
> To: dev@plc4x.apache.org <de...@plc4x.apache.org>
> Subject: Re: BOOLeans ;-)
> Hello Chris,
> Sorry for the late reply, but I've been a little busy lately.
> By the way, I received an offer of to be a committer from PLC4X PCM(sent by
> Hub) a few days ago, and I have already submitted the iCLA document, so I
> would like to thank the PLC4X team for their trust in me.
> To get back to the point, after your explanation I have a clearer
> understanding of coil and register, I thought before that coil storage is
> also continuous storage, so we read regitster's INT and read 16bit coil is
> the same.
> I agree with what you said that we should be writing up how we expect
> different things to be read, and I will improve my code when we determine
> how to do that.
>
> Christofer Dutz <ch...@c-ware.de> 於 2022年10月14日 週五 晚上9:34寫道：
>
> > Hi Ji,
> >
> > well … I know that you can theoretically interpret 8 digital inputs as a
> > byte, but Coils in my understanding are usually directly mapped to
> digital
> > inputs on the Modbus device. So a COIL is technically just a bit … so
> with
> > “coil:1:BOOL[5], you’d be reading coil:1:BOOL, coil:2:BOOL, coil:3:BOOL,
> > coil:4:BOOL, coil:5:BOOL. It would become “problematic if someone started
> > reading coil:1:BOOL[5] and coil:3:BOOL[5] as he’d be reading stuff
> double.
> > Wasn’t objecting this, just wanted to point it out.
> >
> > I guess the reason your INT differs from BOOL-array is that you might be
> > using a LittleEndian PLC and there two-byte values are read in a
> different
> > order.
> >
> > Does that help?
> >
> > I really think we should be writing up how we expect different things to
> > be read and then to ensure all drivers follow that schema.
> >
> > Chris
> >
> > From: jl hong <my...@gmail.com>
> > Date: Friday, 14. October 2022 at 00:55
> > To: dev@plc4x.apache.org <de...@plc4x.apache.org>
> > Subject: Re: BOOLeans ;-)
> > Hi, Chris.
> > I'm sorry to interrupt your trip.
> > 1. Regarding "a coil is a single-valued boolean ...... Not sure what the
> > offset means here?" issue, I just tried it and it works like any other
> data
> > type, but there are 2 small issues to deal with.
> > (1) When we read the INT type, it returns a binary sort of "AB CD", while
> > the BOOL type returns "BA DC", so we need to deal with the binary before
> > reading the BOOL.
> > (2) The Quantity needs to be added to Offset.
> >
> > 2. How to represent the offset and the number of arrays, I think it's
> fine,
> > as long as it's clearly described.
> >
> > Christofer Dutz <ch...@c-ware.de> 於 2022年10月13日 週四 晚上10:10寫道：
> >
> > > Well, I guess mostly I‘ve seen it more treated like: If there’s no “..”
> > > the number is the size of the array, … if there’s a “..” then the
> prefix
> > is
> > > the offset. And yes: the Golang approach is again very different to
> what
> > I
> > > have seen be used in industrial automation.
> > >
> > > Chris
> > >
> > > From: Sebastian Rühl <sr...@apache.org>
> > > Date: Thursday, 13. October 2022 at 09:06
> > > To: dev@plc4x.apache.org <de...@plc4x.apache.org>
> > > Subject: Re: BOOLeans ;-)
> > > In some language I saw that being used as ranges:
> > >
> > > BOOL[5] would be one bool at index 5
> > > BOOL[:5] would be 5 bools till index 5
> > > BOOL[3:5] would be 3 bools from index 3 to 5
> > > BOOL[2:] would be all bools from index 2
> > > BOOL[:-1] would be all bools till the last index -1
> > >
> > > So maybe I'm wrong, but when you write 50000.3:BOOL[5] you mean
> > > 50000.3:BOOL[:5], right?
> > >
> > > Sebastian
> > >
> > > On 2022/10/13 13:40:08 Christofer Dutz wrote:
> > > > Hi all,
> > > >
> > > > seems we got a PR where someone implemented my proposal for handling
> > > Booleans (
> > >
> >
> https://cwiki.apache.org/confluence/display/PLC4X/Cleanup+of+how+we+handle+all+the+bit-related+fields
> > > )
> > > > For Modbus in Go (https://github.com/apache/plc4x/pull/545)
> > > >
> > > > I think we should probably finish some of the discussions on this and
> > > document them in the project.
> > > >
> > > > With the latest discussions on the Browse API and how to deal with
> > > (muti-dimensional) arrays … I think probably a notation:
> > > >
> > > > 50000:BOOL[3..8]
> > > >
> > > > Would be better than:
> > > >
> > > > 50000.3:BOOL[5]
> > > >
> > > > What do you think?
> > > >
> > > > Chris
> > > >
> > >
> >
>