Threads and the Rulbus LabVIEW Library
[User Manual]

Multithreading

Because the Rulbus LabVIEW Library is used on a multitasking--multithreading operating system, attention must be given to the effects this may have. For example, it should not be possible that in one thread a Rulbus device just selected its rack, followed by a second device in another thread setting one of its registers, assuming that its rack still is selected.

The Rulbus Device Library, and therefore the Rulbus LabVIEW Library, enforces the following:

• access to all Rulbus devices is serialized so that only one thread can alter a device at a time and only one device can access the Rulbus at a time
• selecting a rack and reading a byte from or writing a byte to the Rulbus is also serialized

Serialized means that an operation is completed before the next operation will be allowed to commence.

See Chapter 26 of the G Programming Reference Manual [National Instruments, 1998] for more information on multitasking and multithreading in the G Execution System.

Example

The following program example shows the use of three threads, two of which control their own DAC. One thread generates a square wave voltage, the other thread generates a sawtooth voltage.

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