May I know how do I change the sampling rate on a Thermocouple node dynamically through a VI on the host ?
I notice there is a Config node in the "Start" case where I can set the "Sample Interval Mode" to "Host Driven" but I do not know how to continue after that...
Thank you very much !
Host Driven means that the project settings (right-click on the node > Properties) will determine the sampling rate.
What you will need to do to change the sampling rate from the host is to send a message to the WSN node for the host VI (preferably through a user-defined variable) to tell the node to change the sampling rate. Then you can use that invoke node to affect your sampling rate (aka do not use Host Driven).
Is there an exemple how to use user message with WSN, I don't have any idea what to put in the message to chage properties as sample rate or sensor power.
A user message is created by simply right-clicking on the node and selecting "Create User-Defined Variable." Once you set it up, that variable will update over the network automatically.
Once you've got that setup, you need to figure out how you are going to use that variable. You should probably start here: The LabVIEW Wireless Sensor Network Module - Under the Hood
Note: User-defined variables are only available in LabVIEW 2011 for WSN.
Can somebody tell me the differenece between
1. The sample interval in the "START" case in the node programming and
2. The sample interval we get by right clicking on the node >> properties
The sampling rate in the start case is only effective if the sample interval mode is on "VI driven".
If it's on Host driven, then the sampling rate is the one set in the node properties.
Have a nice day