VISA read function in LAb View can not read string from Agilent 33220A

Hi, everyone, I need a help!

Now I write a new program, showed as below:

I can successfully run the program and 33220A also doesn't report any errors.

But the problem is that I can not receive any string and the numeric indicator also shows 0.

I also try to write reset commad, I find 33220A can reset.

Above all, now my situation is that 33220A can reaceive command and do the corresponding reaction, but can not send information back or VISA read function read nothing...............

Note:

 I do not understand that why there is a coercion dot in VISA read function.

Many thanks!