LabVIEW
One VI for 3 different sensors
Hi ammes,
but I am unable to make one VI which integrates all 3 together. Can anyone please help?
What have you tried so far?
Where are you stuck?
Which problems occur?
How does your VI look like?
Did you try to use the example VIs coming with LabVIEW?
Which interface(s)/DAQ hardware do you use to communicate with your sensors?
You have three sensors you want to read from. Do you want to take any actions based on the results, or just read the current values?
When reading the values, should all values be read at the same rate (frequency)? For example, once per second? Or do you want to read the sensors at different rates? Should this be a variable?
If you only need to read the values, first write working VIs for each of the 3 sensors. Then, you can probably copy and paste each while loop into one new VI, with now 3 while loops, and all should run (depending on the interfaces you're using - DAQmx can for example require that multiple channels be in the same task, which will complicate this).
If you only need one rate, you should put all three in the same While loop, and just place them one above another. This would be like copying the contents of each of your 3 While loops into a new loop, rather than the entire loops into a new VI.
Some quick follow-up questions:
- Are you familiar with any other (especially OO) programming languages?
- How much time do you plan to spend on this project?
- Do you need to consider different types of the same type of sensor (e.g. Company A's photo-sensor, Company B's photo-sensor)?
- How much guidance/help can you get from supervisors, colleagues, etc...?
- Which version of LabVIEW are you using?
Ok, so with a week to go it's probably not the time to try too many exotic ideas.
Are all of the sensors connected and communicated with via VISA Serial connections (e.g. RS232 or similar?).
If so, use the sensor manuals to determine the commands necessary to get the values, and use code similar to what you already have to get the other two values.
It might be better to use 3 separate While loops as discussed earlier - each will have its own VISA Resource Name and VISA Configure Serial Port + Close, and in the loops you can use Format to String to structure the messages as needed with the values you need to send. Reading will depend on the response, but either convert directly to numbers as you're doing in the image, if only an image is returned, or use something like Scan from String to get values from a more complicated response.
If turning on and off the lights is done via the same communication as changing the intensity, it might be simpler to have only two While loops and put those two sections in the same loop.
I'm concerned that maybe we're still short some necessary information to make well informed suggestions or give good advice. For example, now you're mentioning a shared bus and microcontroller.
Can you perhaps link to pdf copied of all of the documentation you have for each sensor, or describe in more detail exactly what you're trying to connect to? (Sensor device IDs/part numbers)
What's this microcontroller you mention?
How many USB cables are we talking about? 3 or 1?
In terms of separating a string, can you give an example string that you receive? The actual documentation will probably provide most of the answers needed, so as above, perhaps the best thing to do is upload that PDF.
If you can't give the documentation, the best I can suggest is Scan from String and Format to String with appropriate format strings, but I can't guess blindly what those might be - sorry!
