Hi Haider,
You can't have AI and AO in the same task. You can configure them seperately and have them running in the same while loop.
There's an example that ships with LV that demonstrates this.
Open the Example Finder and browse to Hardware input and output >> DAQmx >> Synchronization >> Multi-function >> Multi-Function-Synch AI-AO.vi
Sarah
Applications Engineer | National Instruments | UK & Ireland