how to repeatly operate window command every half second?

For now, want to perform window command repeatedly every half second, already try to below code, but only perform every one second, how to reduce time interval to half second?

FOR /L %%A IN (1,1,10) DO ( echo i am here )

Solution

Windows timer commands such as timeout and waitfor measure their wait periods in seconds. The only native batch command capable of delaying fractions of a second (without relying on another scripting engine) is ping. If you ping an intentionally erroneous address one time with a -wait parameter of 500, you'll wait 500 milliseconds. Example:

for /L %%I in (1,1,10) do (
    ping -n 1 -w 500 169.254.1.1 >NUL 2>NUL
    echo And I would wait 500 milliseconds, and I would wait 500 more...
)

It seems that half-seconds are as fine as ping understands. Whatever -wait value you specify is floored to the preceding half second. Setting -w 999 will wait half a second. Setting -w 1750 will wait 1.5 seconds.