I'm having a hard time following. The latest popup error screenshot refers to an error in a vi "DAQmx Wait Until Done.vi" which I don't see in the recent code you posted. An earlier description referenced a file with a name related to digital output but you described analog output. The code you attached with a name about digital input instead seems to be doing serial communication.
Have you tried dealing with the things I mentioned back in msg #7? The error suggests that you aren't feeding enough data fast enough to an output task. What have you investigated or changed?
As you mentioned in msg #7 that is for play music vi..but this error occurring while we are generating the signal through PCI 6713 card and SCL HW.vi for tone generation has sent in msg#3
There are general comments in msg #7 about fixed wait times in the producer loop, dual long timeouts on dequeues in the consumer loop, There are some suggestions for improving the code structure.
The errors mean that you aren't feeding enough data fast enough to your output generation tasks. What have you done to investigate further? What is your sample rate for output? What is the value for "Samples to Read" that's used in your producer loop? Are they compatible with the fact that you ALSO have a fixed 100 msec delay in your producer? (I'll bet not.)
Again, I suggested an approach back in msg #7 where you don't artificially throttle the producer loop but instead use a scheme that feeds data as fast as the consumer is able to keep generating it. Have you tried this or any of the other advice I've given?
As it is, your code is difficult to understand in detail at a glance and I don't have unlimited time to struggle through the clutter to figure it out. If you invest some time in cleaning it up, you'll be able to get more people willing to help. Try to keep wires straight as much as possible. Try to limit wire crossings when possible, especially wires of the same color (and therefore same data type).