|
|
Re: FORTE LOVE HTTP [message #1791669 is a reply to message #1791639] |
Tue, 03 July 2018 17:32 |
|
Hi Aydin,
I'm really looking forward to your paper. Seems to be an interesting read.
While I understand your reasons, from a software engineering standpoint I have some issues with your planned new approach. This will introduce hidden interfaces to your application and breaks all encapsulation. This is one of the reason that we currently allow such a wide access only for debugging tools. Therefore I would be curios of other IEC 61499 elements (e.g., subapps, adapters) could help without breaking encapsulation.
On the other hand having a simpler and issue to use HMI support for 4diac is also something we are missing.
The infrastructure for accessing all elements is already in FORTE so from that point there is little work necessary. As path I would go with the "res/subapp1/supp2/FB/var" approach as it is used for monitoring but instead of . with /.
Cheers,
Alois
|
|
|
|
Re: FORTE LOVE HTTP [message #1791691 is a reply to message #1791684] |
Wed, 04 July 2018 08:23 |
|
Hi Aydin,
I think I've misunderstood your post. Could you then please clarify what you meant with this comment:
Quote:One more time, the main challenge is to access basic and later on composite FBs inputs/outputs via HTTP protocol.
Cheers,
Alois
|
|
|
Re: FORTE LOVE HTTP [message #1791695 is a reply to message #1791691] |
Wed, 04 July 2018 09:20 |
Aydin Homay Messages: 5 Registered: June 2017 |
Junior Member |
|
|
Hi Alois,
Maybe I also did not explain very well. I would modify that quote with the following sentence:
The main challenge is to communicate with a basic function block via HTTP based protocols like REST but to achieve this goal we first need to support PUT, POST, GET, DELETE actions on a communication layer like fbdk or maybe if I am not wrong in service interface level. For example, imagine a scenario which on that there is a need to access from a web application or a desktop (windows etc.) application to a basic function block inside of the control system without going through OPC or other heavy and expensive protocols. One way is to put a Pub/Sub function blocks and support HTTP (the way that currently I am supporting it on my local repository FORTE) in fbdk layer but this will make the 61499 application ugly and crowed with so many Pub/Sub function blocks. Hope now this is more clear.
Regards,
Aydin
[Updated on: Wed, 04 July 2018 09:23] Report message to a moderator
|
|
|
Re: FORTE LOVE HTTP [message #1791743 is a reply to message #1791695] |
Wed, 04 July 2018 15:55 |
|
Hi Aydin,
thanks for the clarification. Maybe it helps if I tell how we do it with other HMi like interfaces like Eclipse Neo SCADA or OPC UA. There we have SIFBs (i.e., PUBLISH, SUBSCRIBE, SERVER) which provide the data/event interface from the application to the HMI data model. The main difference to typciall comunication SIFBs is that the communication is not done to a remote entity but to a local data model. HMI or external data sources connect to this data model via the respective communication protocol (e.g., OPC UA) and can then read the latest values and can write to them. On write we typically have a notifcaition mechanism for sending IND events on these FBs. Is this something similar you would like to have?
Cheers,
Alois
|
|
|
Re: FORTE LOVE HTTP [message #1791769 is a reply to message #1791743] |
Thu, 05 July 2018 07:03 |
Aydin Homay Messages: 5 Registered: June 2017 |
Junior Member |
|
|
Hi Alois,
My understanding from the following quote is that you are creating a SIFB which writes/reads into/from the loopback IP 127.0.0.1: Port (localhost: Port) and then a local data model (for simplicity call it a thread) communicates with this SIFB on the same loopback IP address and plays a bridge role between FBs and any other third party data communicator like OPC. Is that right?
Quote:
The main difference to typical communication SIFBs is that the communication is not done to a remote entity but to a local data model.
Regards,
Aydin
[Updated on: Thu, 05 July 2018 13:39] Report message to a moderator
|
|
|
Re: FORTE LOVE HTTP [message #1791818 is a reply to message #1791769] |
Thu, 05 July 2018 15:04 |
|
Hi,
in principle yes. However we ommit the burden of going through a IP based communication. We still have this as part of forte in a background thread and access the model via an in memory API (e.g., a dedicated ExternalEventHandler with API functions to add/remove entities in the data model and methods for updating values, methods for registering SIFBs for receiving updates).
Alois
|
|
|
|
Powered by
FUDForum. Page generated in 0.03732 seconds