Intonation of Text

At lunch Monday, A.M. told me I should avoid texting my kids and "talk to them"!

Oh, I said, to avoid the risk of them having an accident while driving?

"No, not just that but because you need the voice interaction for the intonation" countered A.M.

What really is intonation (was my next question)?  Is it pitch, pace, decibel .....?   And does texting have it's own intonation?

Wikopedia says: "Intonation, rhythm, and stress are the three main elements of linguistic prosody. 

Last night Ellen and I had a texting discussion.  Since she is banned from having a cell phone (long story) we only had texting available (her itouch allows texting).  So starting at 10:06pm and ending 11:21pm Ellen and I conversed.  Twenty nine entries equally divided (sent and received).

(1) There was rhythm (some sent rapidly; others between events - since I stopped while driving home from my Duplicate Bridge Activity).
(2) There was stress - Ellen used all caps: an exclamation point and "...". 
(3) But was their intonation?  Well - sort of (the grammatical part).  Since intonation is used to indicate a question (rising pitch at end of statement).  Several times questions were txted ending in "?".
But A.M. is correct the other parts of intonation are missing - illocution, attitudinal, and informational.

Still seeing the text "i luv u 2"  I could hear the intonation I needed.