Property transfer Definition aspect
I am using property transfer definition aspect to send the AC800M data to a 3rd party OPC Server(running in another computer). I can see the data is reaching the destination computer...but while monitoring the control connection aspect ...I found that those sending signals data quality is sometimes going to bad....I hope this is something coming out of property transfer.....What is the reason for data quality going to bad ?
For testing purpose I have configured 4 signals in property transfer definition and I configured the update rate as 500ms.....even I tried to configure the update rate to 2s...same issue getting....Any idea ?
I have another issue suppose the 3rd partry computer restarted and the data sending from ABB side not changed....then property transfer not updating the 3rd party opc server.....property transfer only writing the data on change only.....I want to write the last value if the 3rd party computer restarted then up and running...any idea ?
Answers
Hello,
Basically what I have personally faced is while interfacing with 3rd part OPC servers, we have a drawback of not maintaining OPC connection continously HIGH.
If we give a New Download, or if the system is made Restarted like you mentioned , the OPC goes down.
Thus Main Problem is : SYNC PROBLEM ( i.e. it losts it Retain syncing files)
One Best solution is Download MATRIKON OPC TUNELLER software(it will weigh 107MB i thnk). Now install it on Both Machines: yours and the other.
Now keep with you a OPC Testing Tool ( like SOFTING or MATRIKON OPC TOOL) for checking availability of all LOCAL & REMOTE SERVERS.
At first check in your same machine only. open Softing and Search in Remote Servers , your ABB OPC should be shown in list and should be browsable also, i.e. you should see further Application,etc in it.
Then go on Second Machine, search similarly for OPC in Remote servers.
If it worked then its best.
ELSE
I can suggest you solutions if you are stuck at site and needs alternative solution to it.
1. There is a software SYNCTOY, it is to be installed on second machine . It actually takes few seconds to establish the lost connection.
2. (GOOD ALTERNATIVE if you are stuck at site)Extract out your ABB OPC software setup from CD,and install it on Second machine where 3rd party OPC server is present.
Now make OPC high in your system-1, and take with your downloaded program in pendrive or something.
Feed Controller IP in your ABB OPC panel of system-2. It should ask you for Missing Retain or Controller Hardware files. Click "Search" and give path accordingly of your program (pendrive).
When all missing files gets collected, your OPC will get OK.
{ NOTE: last solution is an alternative where you will have to make OPC high as mentioned above again whenever it goes down }
If you Google "AKS Property Transfer" you will find many threads where I have written a lot about Property Transfer. Hence I will not write too much here.
One thing differing with your problem compared to the others I have answered before is the bad quality received on the destination OPC server.
The PT does not change quality.
Suggestion: Configure a (temporary) Basic History log on the source property, set a min time equal to the cycle time you have set on the PT and NO max time, log period is up to you (time to detect problem play in). The Basic History log should now mirror the source pretty well*, i.e. what the PT is trying to write to the destination. If the source has bad quality, e.g. due to AC 800M controller download, etc. the Basic History log will show this and you will know the answer why the destination is set with bad.
*) To be 100% sure; you must also temporarily disable the "Allow Parallel Redundancy" on the *source* OPC DA Connector's service group; or else Basic History will enjoy dual feed from the source and a singular OPC server fault will not be reflected in the history log.
I see no other reasons for bad other than that the destination OPC server is not reliable, or is having problems with the writes.
In 5.1 FP4 RevD (or maybe RevE) Property Transfer was enhanced with two new settings:
- Rewrite property even if no change is detected; rewrite every xxx ms.
- Retry failed writes every xxx ms.
These two may add some extra safety to your transfer. In large configurations, especially with a slow destination OPC server, the rewrites may cause a performance problem to go even worse by increasing the volume/frequency of writes posted.
Remember, I still (as I wrote on the other threads) recommend *AVOIDING* property transfer for application critical data, or data involved in interlocks, human protection, important alarm signals, etc.
PLC to PLC communication is best made without involving Microsoft, McAfee, Windows Update, MrNewSoftwareVersion, MrsPatchWithNoImpact, etc.; AC 800M can do plenty of fieldbuses, e.g. Profibus, MODBUS, MODBUS TCP, etc.
Fast and critical data should use some reliable fieldbus or be hardwired IO to IO.
Property Transfer is not intended for critical transfers.
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