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Old April 14th, 2010, 01:38 PM   #1
nitin.salvi
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Issues with Gageport OPC server does not support cimplicity OPC client

I have scanning application in which user scan rate is about 2 barcode scans per second.My current application architecture is as follows.My PC having cimpicty HMI 6.0 service pack4 and Gage port OPC Server used as third party software between symbol make scanner and Cimplicity OPC client application.My problem is that as user scan rate is very high so gageport opc client reports only latest scan value to Cimplicity OPC server so first scan value got missed.

Please suggest me , is there any setting in Gageport OPC server so that my probelm will get solved OR
Is there any other best OPC server which supports scan in milisecond ?
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Old April 15th, 2010, 10:35 AM   #2
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The OPC Client, not the server, controls the scan rate. In this case Cimplicity is probably configured with a poll rate of 1 second. Data is coming in unsolicited to the server but since Cimplicity is on asking to be updated once a second it is only getting the last value. it has been awhile since I last used Cimplicity but I believe the scan rate is set in the port properties. The default is 100 ticks (1 tick is about 10 msec) or 1000msec. You should poll for data from the scanner at least twice as fast as it is coming in. I would set the scan rate to 25 or even 10 ticks.
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Old April 18th, 2010, 10:08 PM   #3
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We already had these setting in Cimplicity Port configuration ( i.e.1 tick ).
We found the actual problem after site visit .Problem is that sometimes gageport OPC server is not showing value quickly when we scan two barcodes in Second.But if we check in hyperterminal , it is showing these value quickly.However when we scan 8-10 Nos of barcode with scanning rate of 2 barcodes/sec then sometimes gageport showing first value only and does not getting updated with next barcodes values.So in our project,we missed these values.Kindly update me why hyperterminal is picking up this value quickly as compared to Gageport OPC server? Also suggest any solution to address above issue?
I am trying to bypass gageport OPC server & testing my application by direcly polling com port with polling rate 200 msec. We got success in this application.But let me know ,Will there any issue like PC hang if i m continusly polling COM port.
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Old April 19th, 2010, 10:20 AM   #4
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There should not be. Barcodes are typically 10-20 bytes in length so even at 9600 baud it would take about 20 msec to get the barcode in. that means that the OPc client has to be able to get the update sent to it before the next scan is done. Hyperterminal is just displaying what is coming in, it does not have to upated another application. I am assuming that the barcode is automatically scanned and you do not have to send a driver to the device to scan it. This means that the data is coming in unsolicited. the server will have to processes that as soon as it comes in.

So say you have cimplicity set for updates every 50 Ticks (500 msec. If you get 2 scans with in that 500 msec you will only get one update to the DA Client (Cimplicity) because it is set to get upates once every 500 Msec and the only think in the servers cache is the last scan that it recieved.

The detailed descriptionis a bit complex and long for an exlanation here. Any OPC training class can explain what is going on.
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Old April 26th, 2010, 07:33 AM   #5
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Presently, we have put intercharacter delay for scanning into symbol make scanner so that operator will scan one barcode per second but still we are not out of the problem.As per latest observation,if we check in gageport without cimplicity project runninng then gageport is getting updated after each scan. But when we are running cimplicity project & checked against device point then sometimes same value is getting logged as per our text file log.Following are the setting we have made in cim project
Port setting:-25 ticks,
Two event :- one event is running on device point update and action is setting value of device point into virtual point.Second event is running on virtual point update & action is filling array point of say 50 element and then one by one picking & validating scanned value from array & then updating into DB SQL2000.

If we scan barcodes say as per following sequence :
123,456,789,654,321,987

then we are getting output at device point as
123,456,321,321,321,987

that means 321 is getting repeated & we are missing 789 & 654 .So please let me know if you have any solution to this problem or give me another alternative ?
pls let me know if you want any additional information to sort out this issue.
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Old April 27th, 2010, 12:32 PM   #6
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Could you get in touch with Kepware Support. We are going to need to have you do som diagnostics captures so that we can compare the communicaitons processing to the OPC Processing. that is going to be the best way to figure out what is going on. Once we do that i would be more than happy to post the solution here in the forum.
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Old April 27th, 2010, 12:58 PM   #7
danw
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Quote:
Originally Posted by Fred_Loveless View Post
Any OPC training class can explain what is going on.
Fred, Where would one find one of these?
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Old April 27th, 2010, 02:03 PM   #8
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We offer training specificly for kepware products which includes OPC Training. You can also get training from The OPC Training Institure, Automation Training, The Technology Resource Center, and Unified Automation. Check out the following web page for links to all.

http://www.kepware.com/Products/services_training.asp
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Old April 27th, 2010, 11:38 PM   #9
nitin.salvi
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After more drill down, we found problem in cimplicity but we could not locate the same.OK,I explain what we have tested yeterday.

As i said earlier, we have two events in cimplicity project.One event is running on scanner device point update and action is to set virtual point(say BARCODE_V) with device point value (i.e. scanned barcode value).In this event,we have put text log file so that we come to know the actual scanned value.
In second event,on virtual point update i.e.BARCODE_V action is to fill array element of 50 then one by one validating array element and updating to SQL DB.

For testing, we made second event disabled and kept running first event which is of setting device point value into virtual point.Then we tested this application by scanning more than 100 barcode with rate of 1 barcode per second.Here we did not found any missed i.e.all scanned value we got in text log file.But when we tested this application with Both event running then we found sometimes same value getting repeated in text log file as i explained in previous discussion.

We could not found any reason that why device point log showing same value when we enabled both events. Please let us know if you have any idea about this problem ?
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Old April 28th, 2010, 09:21 AM   #10
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I cannot tell you why Cimplicty is doing that. The server would only be sending one update to cimplicty for each OPC group when the barcode changes. the only way it would not is if you were forcing reads synchronously or asynchronously. These forced polls tell the server to return all items to the client whether the data has changed or not. You can run OPC diagnoistics in the server and see what is going on between Cimplicity and the server. This is why I highly recommend contact our support team so that they can walk you through this and explain what you are seeing.
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