Dsc opc problem

Hi!
Im trying to connect Labview to Siemens S7-200 with PC-Access OPC server. I tried to use IO Serer and connect it to PCAccess, to PLC. Then I tried to connect it with datasocket to PC Access, and both times i had the same problem. Communication was too slow. For example, when i changed some value in labview, opc server reached that value in 5 seconds. How can i solve this problem?
Thanks

This problem could be because either the scan rate from the PC-access OPC server is too slow, the client program is reading data too slow, or both.
Are you using Shared Variables or Datasocket?
Have you checked the Tag properties on the OPC server? There should be a scan rate from the PC-access OPC server and you can set that rate.
Also, you can check in the tag or variable manager how fast the data is updating.
Regards,
Juan Galindo
Applications Engineer
National Instruments

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Bonjour,
j'utilise LabVIEW 2010 avec son module DSC.
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Attachments:
CreateBoundVariables.JPG ‏40 KB

Hello,
J’ai trouvé une solution mais est-ce la bonne ?!? en tout cas, elle fonctionne.
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doug:
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http://forums.ni.com/ni/board?board.id=190
~~~~~~~~~~~~~~~~~~~~~~~~~~
"It’s the questions that drive us.”
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Hello
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Solved!
Go to Solution.

Thanks NitinD and billko for your answers.
I've already solve the problem, i'll try to explain it (excuse my English please).
Before, I put "DataSocket Open", "DataSocket Read" and "DataSocket Close" in the same loop iteration, without time between open the connection and read from the OPC Server. This made than the result of the reading was '0' all the time. Here we can see a screenshot:
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Regards

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#Software: Microsoft Internet Information Services 8.5
#Version: 1.0
#Date: 2015-05-01 10:37:55
#Fields: date time s-ip cs-method cs-uri-stem cs-uri-query s-port cs-username c-ip cs(User-Agent) cs(Referer) sc-status sc-substatus sc-win32-status time-taken
2015-05-01 10:37:55 fe80::4c44:15cc:9bc6:1455%12 POST /PSDSCPullServer.svc/Action(ConfigurationId='4a90d746-d78e-45e0-9d5d-ca6cac7c0e9b')/GetAction - 8080 PSDSCUser fe80::4c44:15cc:9bc6:1455%12 - - 200 0 0 15
2015-05-01 10:39:10 X.X.X.X POST /PSDSCPullServer.svc/Action(ConfigurationId='e785307e-61a2-419b-8e07-2178295326d9')/GetAction - 8080 PSDSCUser X.X.X.X - - 200 0 0 0
2015-05-01 10:40:59 X.X.X.X POST /PSDSCPullServer.svc/Action(ConfigurationId='7b8d8905-ee40-440c-b20f-4036fcf073a5')/GetAction - 8080 PSDSCUser X.X.X.X - - 200 0 0 78
2015-05-01 10:40:59 X.X.X.X GET /PSDSCPullServer.svc/Action(ConfigurationId='7b8d8905-ee40-440c-b20f-4036fcf073a5')/ConfigurationContent - 8080 PSDSCUser X.X.X.X - - 200 0 0 93
2015-05-01 10:44:45 X.X.X.X POST /PSDSCPullServer.svc/Action(ConfigurationId='67da0c37-24fc-4c3f-bc25-ee81aba879e5')/GetAction - 8080 PSDSCUser X.X.X.X - - 200 0 0 15
2015-05-01 10:44:45 X.X.X.X GET /PSDSCPullServer.svc/Action(ConfigurationId='67da0c37-24fc-4c3f-bc25-ee81aba879e5')/ConfigurationContent - 8080 PSDSCUser X.X.X.X - - 200 0 0 0
2015-05-01 10:49:38 X.X.X.X POST /PSDSCPullServer.svc/Action(ConfigurationId='c8cd8e64-9d55-43a2-9d32-948be8a99003')/GetAction - 8080 PSDSCUser X.X.X.X - - 200 0 0 0
2015-05-01 10:49:38 X.X.X.X GET /PSDSCPullServer.svc/Action(ConfigurationId='c8cd8e64-9d55-43a2-9d32-948be8a99003')/ConfigurationContent - 8080 PSDSCUser X.X.X.X - - 200 0 0 15
2015-05-01 10:51:32 X.X.X.X POST /PSDSCPullServer.svc/Action(ConfigurationId='1d66b01b-0768-4cd0-a639-92c386bc86af')/GetAction - 8080 PSDSCUser X.X.X.X - - 200 0 0 0
2015-05-01 10:51:32 X.X.X.X GET /PSDSCPullServer.svc/Action(ConfigurationId='1d66b01b-0768-4cd0-a639-92c386bc86af')/ConfigurationContent - 8080 PSDSCUser X.X.X.X - - 200 0 0 31
#Software: Microsoft Internet Information Services 8.5
#Version: 1.0
#Date: 2015-05-01 11:10:14
#Fields: date time s-ip cs-method cs-uri-stem cs-uri-query s-port cs-username c-ip cs(User-Agent) cs(Referer) sc-status sc-substatus sc-win32-status time-taken
2015-05-01 11:10:14 X.X.X.X POST /PSDSCPullServer.svc/Action(ConfigurationId='e785307e-61a2-419b-8e07-2178295326d9')/GetAction - 8080 PSDSCUser X.X.X.X - - 200 0 0 15
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2015-05-01 11:11:54 X.X.X.X GET /PSDSCPullServer.svc/Action(ConfigurationId='7b8d8905-ee40-440c-b20f-4036fcf073a5')/ConfigurationContent - 8080 PSDSCUser X.X.X.X - - 200 0 0 31
2015-05-01 11:19:34 X.X.X.X POST /PSDSCPullServer.svc/Action(ConfigurationId='c8cd8e64-9d55-43a2-9d32-948be8a99003')/GetAction - 8080 PSDSCUser X.X.X.X - - 200 0 0 15
2015-05-01 11:19:34 X.X.X.X GET /PSDSCPullServer.svc/Action(ConfigurationId='c8cd8e64-9d55-43a2-9d32-948be8a99003')/ConfigurationContent - 8080 PSDSCUser X.X.X.X - - 200 0 0 0
2015-05-01 11:21:34 X.X.X.X POST /PSDSCPullServer.svc/Action(ConfigurationId='1d66b01b-0768-4cd0-a639-92c386bc86af')/GetAction - 8080 PSDSCUser X.X.X.X - - 200 0 0 0
2015-05-01 11:21:34 X.X.X.X GET /PSDSCPullServer.svc/Action(ConfigurationId='1d66b01b-0768-4cd0-a639-92c386bc86af')/ConfigurationContent - 8080 PSDSCUser X.X.X.X - - 200 0 0 0
#Software: Microsoft Internet Information Services 8.5
#Version: 1.0
#Date: 2015-05-01 11:41:21
#Fields: date time s-ip cs-method cs-uri-stem cs-uri-query s-port cs-username c-ip cs(User-Agent) cs(Referer) sc-status sc-substatus sc-win32-status time-taken
2015-05-01 11:41:21 X.X.X.X POST /PSDSCPullServer.svc/Action(ConfigurationId='7b8d8905-ee40-440c-b20f-4036fcf073a5')/GetAction - 8080 PSDSCUser X.X.X.X - - 200 0 0 78
2015-05-01 11:41:21 X.X.X.X GET /PSDSCPullServer.svc/Action(ConfigurationId='7b8d8905-ee40-440c-b20f-4036fcf073a5')/ConfigurationContent - 8080 PSDSCUser X.X.X.X - - 200 0 0 93
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2015-05-01 11:44:18 X.X.X.X GET /PSDSCPullServer.svc/Action(ConfigurationId='67da0c37-24fc-4c3f-bc25-ee81aba879e5')/ConfigurationContent - 8080 PSDSCUser X.X.X.X - - 200 0 0 0
2015-05-01 11:47:48 X.X.X.X POST /PSDSCPullServer.svc/Action(ConfigurationId='c8cd8e64-9d55-43a2-9d32-948be8a99003')/GetAction - 8080 PSDSCUser X.X.X.X - - 200 0 0 15
2015-05-01 11:47:48 X.X.X.X GET /PSDSCPullServer.svc/Action(ConfigurationId='c8cd8e64-9d55-43a2-9d32-948be8a99003')/ConfigurationContent - 8080 PSDSCUser X.X.X.X - - 200 0 0 15
2015-05-01 11:50:15 X.X.X.X POST /PSDSCPullServer.svc/Action(ConfigurationId='1d66b01b-0768-4cd0-a639-92c386bc86af')/GetAction - 8080 PSDSCUser X.X.X.X - - 200 0 0 0
2015-05-01 11:50:15 X.X.X.X GET /PSDSCPullServer.svc/Action(ConfigurationId='1d66b01b-0768-4cd0-a639-92c386bc86af')/ConfigurationContent - 8080 PSDSCUser X.X.X.X - - 200 0 0 31

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Hello,
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The notes also refer to know issues with NIPALSM but I dont know if this is relavent.
I am not able to access the equipment today but I will find out the software info you have requested tomorrow.
Thanks again
Message Edited by Tony Dean on 05-23-2007 09:15 AM

LabVIEW DSC 2011 / OPC Client IO Server / Can I write to the OPC Server using OPC Groups?

Hi
I am using LabVIEW DSC module as a OPC client. My Shared Variables are binded to automation system OPC Server via "OPC Client IO Server".
On the OPC Server side it seems that the every write commands comes like one item at time, not like grouped.
Now I have tested this with the NI OPC Server as server and KepServer and LabVIEW DSC IO Server as OPC Clients.
When I use the NI OPC Server : OPC Diagnostics there are different events messages when the update request comes from KepServer or LabVIEW DSC.
There are log files on attachements for both write events.
Attachments:
Data from the KepServer.txt ‏6 KB
Data from the LabVIEW DSC OPC Client.txt ‏18 KB

Hello Pentsi,
I have received confirmation (from the PSE in the US) that DSC doesn't support group writes
There however work-arounds that might provide a solution:
- The first solution I had in mind was like this. Update the 50 OPC items as fast as possible.
Then use a 51st item as synchronization OPC item to check/indicate if new data has arrived/has been set/is available.
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In the meanwhile at the LabVIEW side you wait until the 51st value goes back from true to false.
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And this keeps on going...
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Kind Regards,
Thierry C - Applications Engineering Specialist Northern European Region - National Instruments
CLD, CTA
If someone helped you, let them know. Mark as solved and/or give a kudo.

LabVIEW DSC 2011 / OPC Client IO Server / Write by OPC Group...

Hi
I am using LabVIEW DSC module as a OPC client. My Shared Variables are binded to automation system OPC Server via "OPC Client IO Server".
On the OPC Server side it seems that the every write commands comes like one item at time, not like grouped.
Now I have tested this with the NI OPC Server as server and KepServer and LabVIEW DSC IO Server as OPC Clients.
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There are log files on attachements for both write events.
Attachments:
Data from the KepServer.txt ‏6 KB
Data from the LabVIEW DSC OPC Client.txt ‏18 KB

Hello Pentsi,
I have received confirmation (from the PSE in the US) that DSC doesn't support group writes
There however work-arounds that might provide a solution:
- The first solution I had in mind was like this. Update the 50 OPC items as fast as possible.
Then use a 51st item as synchronization OPC item to check/indicate if new data has arrived/has been set/is available.
So LabVIEW sets 50 OPC values as fast as possible. The 51st value becomes goes from false to true when the first 50 values are written.
When this (51st) value is true on the OPC server you can read out the first 50 values (from the non-LabVIEW side). When you've read out these values, then you can set the 51st value back to false (from the non-LabVIEW side).
In the meanwhile at the LabVIEW side you wait until the 51st value goes back from true to false.
When it becomes false, then you write again those 50 values and afterwards set the 51st synchronization value from false to true.
And this keeps on going...
Note: Keep in mind that you only have to monitor one event at the side of the Automation System OPC Server in this case (the 51st) and based on an event occuring over there you can just do a group read of the 50 others. Also keep in mind that the maximum rate (6500 updates per second) from inside LabVIEW with the DSC Module OPC client I/O server was also mentioned in this document (http://digital.ni.com/public.nsf/allkb/63C043359F1E12538625726E005BCD0C?OpenDocument).
Could this be a possible solution for your problem?
If you're using one of the OPC servers in this list (http://zone.ni.com/devzone/cda/tut/p/id/6417#toc19), then you can also use NI OPC Servers to update tags instead, which supports a faster update rate.
Kind Regards,
Thierry C - Applications Engineering Specialist Northern European Region - National Instruments
CLD, CTA
If someone helped you, let them know. Mark as solved and/or give a kudo.

Can I import items from the CAENHVOPCServer2.2 to DSC ?

I'm just starting to test DSC. I see I can import channels defined on NI DAQ (PCI) into the configuration file of the tag engine just using the configuration Wizard. On the other hand, I've installed on the same PC the CAEN HVOPCserver2.2 whose items are visible through the configuration wizard, but Labview (6.i) get stack when tryint to add channel dependent items to the conf. file.
I've also updated NI Logos to ver. 4.4 but this doesn't help.
Did anyone experienced (or solved) these problems ?
Thanks.

Hi Stefania,
Did you try to connect from another OPC Client to the CEAN HVOPCserver?
A good link is our troubleshooting page for OPC and DSC: Tools for Troubleshooting OPC Interface Problems
If LV DSC isn't the only OPC client to have trouble, than we would know that there is something wrong in the OPC Server implementation. I suspect that other OPC clients will as well, since LV DSC OPC client works with other OPC servers.
When the TCE uses the server, it creates a group and adds items to it, and validates the items. It never activates the items. Then, we remove the items and remove the group. Some time right after we release the group, th
e server could cause a crash in our code. Possibly it's calling into our group after it's been deleted? Or something similar?
Given that our OPC client works with dozens of other OPC servers without exhibiting such behavior, it is maybe a server bug.
We have seen similar behaviors with other various OPC servers.
E.g. The server is deliting an object that provides the interface "IEnumOPCItemAttributes" when we still have a reference to it. This violates the IUnknown interface contract.
We can avoid their bug by releasing our interface prior to informing the server that we're done with the group.
This change is encountered in the LabVIEW DSC 6.1 Release.
A patch that avoids this bug in the Servers is attached for LV DSC 6.0.2.
Could you try the attached DLL with your OPC server? If this does not help you might contact the OPC server company for the latest version or/and you contact National Instruments support directly, thus the Applications Engineer can reproduce the beha
vior.
Hope this helps
Roland
National Instruments
PS: the file belongs to \vi.lib\system"
Attachments:
LVOPCClient.dll ‏293 KB

OPC - packages to buy

Hello.
So far I have been using RS232 to talk with PLC like siemens. It works good bot takes too much time to develop. OPC seems to be easier because I don't care about communication.
So If I want to use OPC from NI what do I need to buy? I was reading descriptions but that's not clear for me.
So far I need:
1. NI OPC SERVERS
http://sine.ni.com/nips/cds/view/p/lang/pl/nid/209059
This will take care of communication with any kind of PLC listed here: http://www.ni.com/white-paper/6417/en/#toc41 ?
What it means that I can have , 1 Simultaneous Driver Usage or Unilimted?
2.Dataloging and Supervisory Control Module - this allows labview to talk and exchange data with OPC ?
http://sine.ni.com/nips/cds/view/p/lang/pl/nid/1010
3. DSC Run-Time system
LabVIEW DSC Module Run-Time System for Windows - what is that for??
Having all of that can I compile and deploy exe that will talk with plc via opc??

Datasocket works but has the drawback that is operates synchronously. If your OPC server is slow or doesn't react for some time then this datasocket read will block that part of your diagram completely. Not a problem if you only communicate with a few OPC items but definitely not scalable to larger systems. The DSC OPC client interface uses OPC advise to read values where the OPC servers push item values to the DSC engine whenever they have a new value to report. An OPC server being slow or not reacting won't delay the update of other OPC server items.
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

Dsc opc problem

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