Streaming from a LabJack is what is called an asynchronous action. This means that the LabJack does its own thing and every so often it tells DAQFactory that there is new data or there is an error. For this reason, you cannot simply look at the error code returned by LJ_ioSTART_STREAM to catch all stream errors. This command may return a stream configuration type error, so you'll want to check for it using the same methods as the low speed acquisition, but will not handle errors in the actual stream. For this you have two choices:
1) You can create a simple sequence to retrieve the last stream error continuously and do something if it returns an error. The function GetLastStreamError() will return the code for the last stream error. This is reset when you start the stream. This, however, is not the best way to do this and will waste processor power.
2) You can use the DAQFactory OnAlert event, which only gets called when an actual error occurs. Using the event as an error handler is described in the previous section on error handling, and catching stream errors would be done the same way. One common error you might want to catch is if your LabJack accidentally gets unplugged while streaming. If you wanted to automatically restart streaming when it is reconnected you could do this in your OnAlert sequence:
if ((left(strAlert,10) == "D0050:00:2001") && (Streaming)) // 2001 is LJE_RECONNECT
StartStream()
endif
Now, this assumes that you have a sequence called StartStream that will reconfigure the LabJack and actually restart the stream. It also assumes that you've created a global variable called "Streaming" that you set to 1 in StartStream, and to 0 in StopStream. This is so an accident unplug when you aren't streaming doesn't spontaneously start the streaming process. Finally this assumes you are using device number 0 / first found. Please see the section on OnAlert if you are using multiple LabJacks.
