Hi
I am Aniket I need to ask any worked with any apm devices for Data Acquisition System (DAS) and in that for datalogging through mavlink osd.

 I am new to apm programming. I have been working on rc airplanes from d past 3 years but i have no idea about apm and its usage. I recently bought a 3dr telemetry kit along with d apm. I need ur help regarding apm 2.5 to perform a certain task. The task goes as follows:
1. I have to monitor and display the flight data onto the ground station using my telemetry kit and OSD. Altitude and airspeed shud be displayed on the ground station.
2. I have to drop a package using a servo motor and then the altitude from which i dropped d package shud be displayed onto my laptop screen.

Could u help me write a program regarding d same. If not ,can u please give me someone else's contact who would be able to help me out.
Regards
Aniket92

You can log data via mavlink with telemetry or APM can log it onboard. OSD can only overlay the data stream form telemetry onto video feed as far as I know.

http://code.google.com/p/ardupilot-mega/wiki/Datalogging
http://plane.ardupilot.com/wiki/common-mission-planner-telemetry-logs/

Thank you
But i want datalogging in real time during fight.

hi aniket !
data log through out the flight will be saved on laptop , if you are using mission planner! for continuous and complete data log you need to have good link between mission planner (modem)  and air vehicle. some log will be saved on APM , but as soon as you switch it off and initialize for next flight older log will be erased automatically.
After retrieving  data log , you can play same flight on mission planner