Re: [PATCH v10 0/7] Add Fieldbus subsystem + support HMS Profinet card
From: Enrico Weigelt, metux IT consult
Date: Tue Apr 16 2019 - 12:51:18 EST
On 15.04.19 20:31, Sven Van Asbroeck wrote:
Hi,
>> Maybe it would be better calling it "IEC-61158" instead of "fieldbus" ?>>> > Yes, we are certainly open to that, if it is more correct and/or
better> accepted by users.
Thanks, I'd really appreciate that :)
Maybe I'm a bit beaurocratic here, but I really believe that precise
naming is important, eg. for avoiding potential conflicts w/ different
fieldbus classes (eg. mvb) that might come in the future.
> Yes. You can open as many handles to the device as you like,
> they will all share the fieldbus memory. When the remote
> fieldbus memory changes, that event will be broadcast to
> all open handles, via poll/select.
Great. When I read your first mail, I got reminded on the old legacy
canbus chardevs (before cansocket came in) that was single-user only.
By the way: any special reason for doing this via device instead of
socket (like we have w/ can) ?
I'm, personally, pretty undecided which way is better. Device nodes give
us easy access control via fs permissions, while socket allows
firewalling.
--mtx
--
Enrico Weigelt, metux IT consult
Free software and Linux embedded engineering
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