Question for your AD7891 ref output

Dear Sir/Madam,

I have some questions for your AD7891.

When we use by standby mode for AD7891,

1)Does REFOUT(2.5V) stop, when AD7891 doesnt convert for a long time?

2)If we do the soft-standby mode, then REFOUT stop the 2.5V output, correct?

  If so, after AD7891 start the A/D convertion, then REFOUT start to output 2.5V correct? 

3)No matter what the  /STANDBY pin is pulled up to high by external pull-up resister,

after we make change that put 1 on SWSTBY, is your AD7891 changed to standby-mode?

4)We are watching 2.5V output during AD7891 is standby mode also.

When it is the standby mode, REFOUT seems to become no-control action.

I cannot catch these on your datasheet well.

Thanks Kaos