Example: DSReader
Reads values from different data sources using dstp, logos, opc, http, ftp, or file protocols.
Description
Through National Instruments DataSocket technology, your programs can communicate with a variety of different data sources. In this example, you can either manually type a data location for Source or select one of the sources from the listbox.
DataSocket supports the following types of connections:
| Protocol | Examples |
|---|---|
| DataSocket Server ("dstp:") | dstp://localhost/wave |
| dstp://machine/item | |
| Standard Web Server ("http:") | http://www.ni.com/cworks/datasocket/tone.wav |
| Standard FTP Sites ("ftp:") | ftp://ftp.ni.com/datasocket/ping.wav |
| The ftp site should allow anonymous connections. | |
| Lookout/Logos objects ("lookout:" or "logos:") | lookout://localhost/testprocess/pot1.value |
| logos://localhost/testprocess/pot1.value | |
| Files directly accessible from your file system ("file:") | file:ping.wav |
| file:c:/mydata/ping.wav | |
| file://machine/mydata/ping.wav | |
| OLE for Process Control (OPC) Servers ("opc:") | opc:/National Instruments.OPCDemo/sine |
| opc:/National Instruments.OPCDemo/sine?Accesspath=sine | |
| opc://machine/National Instruments.OPCModbus/Modbus Demo Box.4:0 | |
| opc://machine/National Instruments.OPCModbus/Modbus Demo Box.4:0?updaterate=100&deadband;=0.7 |
Controls, Properties, Methods, and Events
This example demonstrates the following controls, properties, methods, and events:
ConnectTo, Update, Disconnect, OnDataUpdated, OnStatusUpdated
Example Location
Samples\DataSocket