using opc in labview - example
TRANSCRIPT
Using OPC in LabVIEW
1 Hans-‐Pe5er Halvorsen, Telemark University College, 2013.02.19
Example: Logging Temperature Data using OPC
Equipment • Hardware:
– NI USB-‐TC01 Thermocouple Measurement Device (or NI USB-‐6008 DAQ Device)
• SoNware: – LabVIEW 2012 – DAQmx Driver – MatrikonOPC SimulaMon Server
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What is OPC?
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• OPC -‐ “Open Process Control” • A standard that defines the communicaMon of data between devices from different manufactures
• Require an OPC server that communicates with the OPC clients
• OPC allows “plug-‐and-‐play”, gives benefits as reduces installaMon Mme and the opportunity to choose products from different manufactures
• Different standards: Real-‐Mme data (OPC DA), Historical data (OPC HDA), Alarm & Event data (OPC AE), etc.
What is OPC?
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The user are free to choose the best suited devices, controller and applicaMon for their project without worrying about which vendor each came from.
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What is OPC?
E.g. a PLC
OPC is the world’s most popular standards-‐based data-‐connecMvity method. It is used to answer one of the automaMon industry’s biggest challenges: how to communicate between devices, controllers, and applicaMons without ge`ng caught up in the usual custom driver-‐based connecMvity problems.
GeXng Started with the NI USB-‐TC01 Thermocouple device
Once the device has been successfully detected, the NI USB-‐TC01 Launch Screen will open (as shown in Figure below), or a Windows “Autoplay” dialog will appear allowing you to select “TC01Launcher.exe” to run the sobware.
TC01Launcher.exe
Note! If “Autoplay” does not start or it is disabled, locate the NI USB-‐TC01 under “My Computer” and double-‐click “TC01Launcher.exe” to manually run the sobware.
The NI USB-‐TC01 has a green LED next to the USB cable to indicate the device status. When the LED is illuminated, the device is powered and ready for operaMon. If the LED is not illuminated, the device is not powered or did not iniMalize.
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NI USB-‐TC01 Thermocouple Measurement Device – Temperature Logger
Run the Temperature Logger to check if the device works as expected before you start on your LabVIEW Programming 9
Open the Log File to see the data
How-‐To use the NI USB TC-‐01 Thermocouple Device in LabVIEW
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The USB-‐TC01 Device works similar as the USB-‐6008 DAQ device, i.e., you use the DAQ Assistant in LabVIEW
NI USB-‐TC01 Thermocouple Measurement Device using LabVIEW
The USB-‐TC01 Device works similar as the USB-‐6008 DAQ device, i.e., you use the DAQ Assistant
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DAQ Assistant for NI USB-‐TC01
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Acquire Signals » Analog Input » Temperature » Thermocouple
Select Physical Channel ai0
Use default ProperMes
Click OK to Finish
Temperature Simulaaon
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If you don’t have a TC-‐01 device, you can create a simple “Temperature Simulator”
A simple SubVI that simulates a Temperature value using a Random Generator
In this way you can easily switch between the real Temperature sensor (TC01) and the Simulator
Case Structure
Case Structure
While Loop
While Loop
OPC
Matrikon OPC Simulaaon Server
LabVIEW
OPC Server
OPC Client
OPC DA
Matrikon OPC Explorer
COM/DCOM
We will use the Matrikon OPC SimulaMon Server – which is a free of charge OPC Server for test purposes.
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Note! Normally, the OPC Server and the Clients are not on the same computer, but in this assignment we will for simplicity have everything on the same computer.
OPC Client
OPC Client
COM/DCOM COM/DCOM
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Matrikon OPC Explorer -‐ Add Tags
Use the BucketBrigade Items – because they can be used for both reading and wriMng
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Use OPC Explorer to Check Communicaaon Run the LabVIEW program and use the Matrikon OPC Explorer to check if the data is correctly wrihen to the OPC server from LabVIEW
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Aliases In the “Matrikon OPCServer for SimulaMon” you can create Aliases . Aliases is handy when you want to describe your OPC items using more realisMc names, e.g., we can create an alias called “Temperature” for the “Bucket Brigade.Real4” item. This is more descripMve and easier to remember.
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Temperature
You may right-‐click to create one or more Alias Groups
Right-‐click to create a New Alias 1 2
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Type an Alias Name and other se`ngs here
Scaling/Converang in the OPC Server
𝑇↓𝐹 = 9/5 𝑇↓𝐶 +32
The OPC server can automaMcally scale/convert values for you, e.g., from degrees Celsius to degrees Fahrenheit
We can create different aliases, e.g., “Temperature Celsius” and “Temperature Fahrenheit” 20
OPC in LabVIEW
The DataSocket palehe in LabVIEW:
Write Data to OPC
Read Data from OPC
Open ConnecMon to OPC Server
Close ConnecMon to OPC Server
Browse OPC Servers and OPC Items
You can use LabVIEW as an OPC client by connecMng to an OPC server through a DataSocket connecMon.
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Use OPC Explorer to Check Communicaaon
You can manually change data in the OPC Server using the OPC Explorer
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Log Data to File
Simple Example of how to log data to a Measurement File using the “Write To Measurement File” funcMon in LabVIEW
In this example we just generate some random data. In your case you shall log the data received from the OPC Server
You can turn logging On/Off 26
Log Data to File -‐ Properaes Recommended Se`ngs in the Properaes Window (Right-‐click on the Write To Measurement File icon):
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Measurement File – Data Visualizaaon Open the File with Logged Data in e.g. Notepad:
Open the File with Logged Data in MS Excel and create a Chart:
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Make sure to format number of Decimals
SubVI – Scaling from Celsius to Fahrenheit Front Panel:
Block Diagram:
Create an Icon in the Icon Editor
Define Input and Output Terminals
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Addiaonal Resources
• NI USB-‐TC01 Thermocouple Measurement Device
• Data AcquisiMon in LabVIEW • OPC and Real-‐Time Systems in LabVIEW • IntroducMon to Visual Studio and C# • Data AcquisiMon in C#
30 h5p://home.hit.no/~hansha/ The resources are located here:
Hans-‐Pe5er Halvorsen, M.Sc. Telemark University College Faculty of Technology Department of Electrical Engineering, Informaaon Technology and Cyberneacs
E-‐mail: [email protected] Blog: h5p://home.hit.no/~hansha/
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