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Unable to run as service

17 Jan 2012 09:25 #746 by support
"CreateObject" run a combination of code on the client side (in this case, the Xbase++ code for it), and a code of the component itself (if it successfuly manages to connect to it). Therefore the problem can be on either side.
I have some questions:

Have you waited "long enough", i.e. isn't there actually some error message, but after a long time? I am asking because the function needs to start a separate process and wait before it registers its class factories with COM, so there is a wait operation inside Microsoft COM that is supposed to eventually time out if not eveything goes right.
When your code reaches the "CreateObject", can you actually see the "easyopcl" process starting in Task Manager? If not, then this a client side or service/COM configuration problem, because our code does not get a chance to run. If, on the other hand, our process is starting, we will need to investigate further in this direction.

Thank you

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11 Jan 2012 18:21 #745 by Jack_Duijf
Thank you for the reply.
It seems that the folowing line of Xbase++ code freeze the thread (never returns).
::oOpc := CreateObject("OPCLabs.EasyDAClient.5.1")
The same code does run when started from a destop application.

I followed all instructions, i set the login for the service to system account and to administrator, but no improvement there.
I reported this error to Alaska support, the function CreateObject() should never Freeze.
Jack Duijf

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10 Jan 2012 13:04 #744 by support
for current instrucions to registering the component as a service, please see the main "Concepts" document (installed with the product, or <a href="" target="_blank" rel="nofollow">, and look for the "COM Registration and Server Types" heading.
In general, all combinations are possible (your application as an application/a service, and EasyOPC component as an application/a service), but they may require different settings - especially around security. The security is also most likely the cause of your problem. Services run under accounts they are configure to run in Service Manager; and, if they are DCOM components, they are influenced by the settings in DCOMCNFG. It is is necessary to give permissions to proper accounts to launch and access the component - and the OPC server; and, in fact, also your client - because the component is making callbacks (if you are using subscriptions).
For start, we need to know what kind of error are you getting?

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10 Jan 2012 00:09 #743 by Jack_Duijf
My xbase++ OPC client application runs fine when started as a Windows application.
When run as a service, i am unable u connect to the OPC server.
I make a connection via COM "OPCLabs.EasyDAClient.5.1".
I search on this website, and found some references, but was unable to open the link.
The link
I was also looking on my harddrive for eopcdal.exe (should i run eopcdal /Service ??) but was unable to locate this file.
How to proceed?


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