09-29-2008 08:06 AM
hello,
The lab i'm working in uses labview to perform spectroscopy measurement.
would this be possible: one while Loop "A" that receives data through GPIB at a desired interval of time, and one while loop "B" that receives data from another GPIB instrument and then output a byte of word through serial comunication. Loop A works perfectly on its own..but if i try to run both loops together, would there be conflicts? if no, then loop A i'd like to run at user defined interval of time ,and loop B as fast as possible. would that be possible?
thank you very much for your help!
***The following is supplemental information on the loop as it is not necessary unless interested in knowing***
we have a GPIB instrument that reads voltage of our sample and a simple mathematical equation converts that to a temperature, and we 'd like to read that temperature constantly and as it changes, we change the output of our PIEZO box (a thing that can output from 0 to 10 volts of current). piezo box uses the standard serial communication. so in a way a simple/fake PID loop to keep the temperature stable. the output of piezo is connected to a thermocouple which heats up our sample.
the same time, we also have a "camera" that is communicating through GPIB, that records the spectrum of the sample and display it on a XY graph. we'd like that camera being continuously running as well. so it will keep taking picture one after another interval of 1 second at the same time as the first loop keeping the temperature stable.
09-29-2008 10:00 AM
You can have two While Loops running in parallel. You can even code it so that they use a particular CPU code.
However, the GPIB bus does not support parallel communication. It can be near "parallel" especially if coded in such a way to synchronize the commands, but they may get to the instruments a few ms apart. That is a restriction on the GPIB bus, not within Labview or the While Loops.
R