| OPC UA Server Client [message #1783514] |
Tue, 13 March 2018 18:40  |
 Anugerah Nuri Satria
Messages: 32
Registered: September 2017 |
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Dear Mr.Alois
My Undergraduate thesis looks for an analysis effect of difference of fb architecture to value of quality of services, its means that i make any program who have a different architecture like star, line and etc ( topology) , . I use OPC UA communication protocol,
I will ask, how to refresh the value of the timer, both timer on and time period? because i have some inputs when the program is running. The scheme which I use is the automotive industry that wants the flexibility of products like car body color in indystry 4.0 era. Therefore I should be able to run a program that can able two inputs while running and refresh the previous data. That scenario is describe in this image.
and second problem, when i try run this programs, at QX output "merah_0" has "TRUE" value in client, and i try to connect with raspi, but at gpio raspi can't switch on the lamp.
I use opc ua client and server to communicate all of them.
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| Re: OPC UA Server Client [message #1783669 is a reply to message #1783634] |
Thu, 15 March 2018 11:43  |
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The FB_TON and most other FBs you are using in your application are ported standard IEC 61131-3 function blocks. they first require a regular invocation, in our case via the REQ event and then to get the intended behavior you need to follow the definitions for the fBs according to IEC 61311-3. For the TON that means that it delays any rising edge of its input. So for resetting the timer you need a falling edge of your boolean input.
May i also add that some of your functionality could also be quite easily be implemented using IEC 61499 basic function blocks. There you could take more advantage from the event based nature of IEC 61499.
Regarding you QX problem. As already pointed out by Jose you have not connected your init events. that means that the QX block is never initalized and therefore not able to write to the outputs. By enabling 4diac's monitoring feature you could see this on the output values of teh QX FB.
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| Re: OPC UA Server Client [message #1783738 is a reply to message #1783708] |
Fri, 16 March 2018 12:54 |
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If these FBs would all be within the same device there will no or not much difference. If it is over the network there I would expect differences. But the differences would also be influenced by the communication protocol. If you are using for example the default 4diac Etherent communication according to the "IEC 61499 Compliance Profile for Feasibility demonstrations" then Publish and subscribe would utilize UDP multicast. So in your top left case there would only one message be sent over the network while in all other setups more messages. If you take the current available OPC UA implementation there you have always point to point TCP connections between sever and client you would have in all cases 4 TCP messges be sent. This may change in the near future when OPC UA pub sub will be available.
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