electronic delay

[yukfai88]

Hi, everyone.

I have built a program for reading continuous message from a GPS receiver as attached. But as it needs time for LabView program to work and display the message from the receiver, and thus the message shown is always delayed by the electronic execution of the program. Is it possible to measure the electronic delay of execution of the program in my program? Can anyone show me the way how to modify my program so as to include accumulated electronic execution time in my program. Thank you very much.

Best Regards,

yukfai88

[Dennis_Knutson]

The only delay I see would be coming from the instrument and not the program. Do you want to measure the time it takes for the instrument to update?

[LV_Pro]

As Dennis points out, the instrument will have a delay in updating. There will also be the delay inherent in communicating over a serial link, at both ends. In you program you could determine the loop time as shown below, but I'm not sure how useful that is. It just shows how long between messages, doesn't tell you how long from the time the instrument (GPS in this instance) updates its time calculation to when it shows up in your program. It only show how long between received messages. If you could calculate, using external means, some delay between the GPS updating/sending the message and when it is displayed it wouldn't tell you much unless you could make those measurements each time, as it probably will vary.  The "0" case just passes the timer through.

[LV_Pro]

The "Dbl" indicator is mislabelled as mS, it is actually in seconds, but will show .001 seconds, which is are milliseconds. I had originally used timer ticks, which are in milliseconds, but there is an issue with the timer tick value "rolling over to zero" when the count gets over 4294967295 mS, ((2^32)-1) roughly every 49 days.