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From: =?UTF-8?Q?Bj=c3=b6rn_Lundin?= <b.f.lundin@gmail.com>
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Subject: Re: Simple Components 4.12 with MQTT implementation released
Date: Thu, 14 Apr 2016 23:03:46 +0200
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Date: 2016-04-14T23:03:46+02:00
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On 2016-04-14 18:47, Dmitry A. Kazakov wrote:
> On 2016-04-14 15:01, slos wrote:
> 
>> Anyone for OPC ? ;-)
> 
> Well, which of?
> 
> OPC DA is, truth to tell, garbage.

Yes.


> OPC UA is under permanent development. It is impossible to say when it
> will reach even a semi-standard stage.

Iteresting. Never heard of it.
But we left the OPC-world 10 years ago,
when we realized it is much better with direct socket
with some protocol we PLC-guys and we could agree upon.

> 
> Regarding architecture, OPC is barely usable in automation because of
> its heavy client/server architecture. Part of our business is to replace
> OPC with better middleware architectures. Replacement works smoothly
> because in most cases you can throw out the OPC server and communicate
> with the hardware directly. E.g. most SPS' support either ITOT or
> ModBus, each far superior to OPC.
> 

The only real advantage I can see is the OPC-scout - a way of
browsing raw data in the plc.
But that is for manual use, and troubleshooting,
so for 'office' use I can see OPC as something not too bad -
hence why I wrote down the opcda code in another answer.
For automation - other protocols are better


-- 
--
Björn