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 <[email protected]> Date: Friday, 14. October 2022 at 00:55 To: [email protected] <[email protected]> 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 <[email protected]> 於 2022年10月13日 �L四 晚上10:10��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 <[email protected]> > Date: Thursday, 13. October 2022 at 09:06 > To: [email protected] <[email protected]> > 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 > > >
