Hello, I'm relatively new to LabVIEW, and am experiencing a problem and would be extremely grateful to anyone who can help!
Basically I have a number of proximity sensors attached to the back of a climbing wall. As someone climbs the wall, data is sent to the computer about the wall deflections. A VI (called data.vi) takes the data, and through a number of filters, completely reduces noise in the signal. I then have another VI (called main.vi) which displays the data onscreen through its front panel. This VI is quite complex and uses a number of while loops within its block diagram. The data.vi does not talk directly with the main.vi, with another vi (called channel.vi) acting in between. Channel.vi is a sub vi of main.vi, and data.vi is a sub vi of channel.vi. Channel.vi exists because, main.vi was built on a different computer away from the climbing wall. Hence wiring data.vi into channel.vi was a quick way of implementing the system. A final fourth vi is used (called random.vi). This VI just generates random data, and can be used as a sub Vi in channel.vi instead of data.vi. This allowed main.vi to be tested away from the climbing wall with dummy data instead of real data. Now if I run main.vi, with channel.vi as a sub VI, and random.vi as a sub VI to channel.vi supplying dummy data, then main.vi runs fine with Windows XP saying approximately 30% of the processor is being used. If I run channel.vi, with data.vi running as a sub VI inputting real data from the wall, then the front panel of channel.vi shows the data real-time, with Windows XP again reporting about a 30% processor usage. However if I run main.vi, with channel.vi as a sub VI, and data.vi as a sub VI of channel.vi, (the intended system), it runs very slowly with data being updated every 5 seconds or so, on the front panel of main.vi. As stated above, main.vi does contain a number of while loops, and I have experimented by putting millisecond delays between each cycle of the while loops, to ensure the processor does not reach 100% usage, but to no avail. I am using LabVIEW 7 Express, not on a great machine (Celeron 800MHz, 256Mb of RAM, 8Mb shared video RAM) - am I asking too much? Help! Any comment would be greatly appreciated. With thanks Lawrence
