ML-l3 wireless problem

[Linmax]

I am trying to use a Nikon wireless shutter release (ML-L3) with my D600 camera. It works well except after a short time the camera seems to go into sleep mode and at that point the remote fails to activate the camera's shutter. I have extended the time on the 'standby shutter' but that makes no difference. What am I missing? Suggestions please.

 

[Linmax]

Also extended (standby timer - C2 menu item) but still doesn't work?

 

[nickt]

'Remote On Duration' is what you want, menu C5. It only goes up to 15 minutes unless you have some activity. I think a half press of the shutter button on the camera restarts the timer. It does use a lot of battery.