Bonjour, est-il possible d'interroger un serveur OPC avec PROVIEW ?

Merci

Hi,

OPC XLM-DA client and server are implemented in Proview. To communicate with for example OPC DA you need a gateway.

/Claes

Hi Claes,

To connect to an industrial OPC DA server, we've been searching for gateways and settled on Kassl software. Kassl is a German-based company: www.kassl.de/opc/index.shtml

In particular, we are interested in Kassl's dOPC XGate software to "enlarge a targeted COM DA based OPC server with an OPC XML-DA interface". Kassl offers a free trial of dOPC XGate, but also a free OPC Mobile Explorer for Android via Google Play for testing their XGate software. The software is certified OPC Foundation compliant and comes with two public OPC XML DA server URLs for testing purposes. Of course, Kassl's OPC Client works flawlessly with the two test servers:

Public OPC XML-DA Server #1
opc_provider, opc_provider, noload, run, opc_provider, 4, nodebug, advosol.com/xmldademo/ts_sim/OpcDaGateway.asmx 0.1.99.55 MyOpcVolume

Public OPC XML-DA Server #2
opc_provider, opc_provider, noload, run, opc_provider, 4, nodebug, opcxml.demo-this.com/XmlDaSampleServer/Service.asmx 0.1.99.55 MyOpcVolume

For testing purposes, a Proview project is configured with an OPC Client and an OPC Server. When Proview's OPC Client is connected to it's own OPC Server, everything works perfectly.

When the Proview OPC Client is connected to either public test server, a connection is made and the OPC Client $Mount Object browses the public OPC test server database OK. But, values do not update. The Proview Development Console indicates the following error:

Error 400 fault: SOAP-ENV:Server [no subcode]
"HTTP Error"
Detail: HTTP/1.1 400 Bad Request

When connecting Kassl's Android OPC XML-DA client to Proview's OPC Server, the following message is displayed:

"Unable to connect to OPC server http://192.168.2.204:8080, invalid time offset"

Proview OPC Server Client Access is given to my Android device, 192.168.2.5, port 8080 with Access ReadWrite. Interestingly, Proview OPC Server indicates a connection is made even though Kassl's client indicates no connection.

I read an old thread by Bernt-Johan working through various OPC bugs. Did he ever delivered his code patches to you? I see similar symptoms that he claims to have solved: www.proview.se/v3/index.php/forum/4-prov...ntation?start=6#4214

Do you know of any commercial OPC XML-DA gateway software that is compatible with Proview?

Regards,
Ron

Hi Ron,

I think that some clients check the time stamp and that it's important to have the same system time in client and server. This may be a cause to the 'invalid time offset'.

We bought a gateway many years ago when we developed the OPC server and have used it since then. I don't recall the manufacturer but I'll be back with this.

/Claes

Hi Claes,

Currently, I'm in the process of learning all about SOAP and XML-based data transfers with a strong emphasis on the OPC Foundation's published communication specification and XML-DA WSDL data structure. Not surprisingly, Proview's 5.4 opc.wsdl file does exactly match the OPC Foundation's last version 1.1. Also, a SOAP tester was loaded and I am learning by running many experiments against various public SOAP databases, not necessarily OPC compliant. SOAP is new to me, but already can appreciate the power of the XML and WSDL structure. All of this effort is two-fold:

1) to reconstruct the previous OPC debugging efforts of Bernt and Johan.

2) to understand and explorer SOAP for interconnecting many SQL databases located at many sites across the US to a centralized corporate reporting server.

Thinking out-loud: Since SOAP databases are WSDL defined, it seems Proview's OPC Server and OPC Client could possibly support other SOAP database structures, not necessarily OPC compliant?

Thanks for looking into Proview compatible gateway software. Finding a compatible gateway to connect to various industrial OPC-DA servers is a critical project path.

Regards,
Ron

Hi Ron,

I finally got information about the OPC gateway that we use. Previously it was an OPC XML Server Gateway from Kassl which usually worked fine, but sometimes some strange hanings occured. The one we use now is an OPC XML-DA Client from Kepware Technologies.

We use an open software named gsoap to handle the SOAP communication. gsoap generates c-structs and function stubs from the wsdl-file, and then some code has to be written to fill these structs with data (requests) or analyse the received data (replies). So it's not possible to use the OPC communication for any other SOAP server, some new code has to be written for each server.

/Claes