This is just an informational message (as seen by the icon). So you can safely ignore it.
Thanks very much for your response. You mean that I can ignore this error message? in another words, this message is a bug?
tl;dr: Yes. No.
Yes, you can ignore this message. It neither an error nor a warning, its purely informational.
No, I don't think its a bug, it actually tells you the truth: Vref is actually _not_ connected to a terminal - you are using internal Vref. (So this message should not appear when you are using external Vref, or even when using buffered Vref [which is preferred anyway])
Cypress might consider it a bug that the write internal (debug?) messages to the console log.
The only bug here might be that the signal seems to named wrong: its _vdac_ref_ whereas it probably should be _vadc_ref_.
Thanks again and again for your help.
One more thing is that I tried to use three Wave DAC8, but some one no output and some output is clamped, I checked everything and they seem good.