Problems in Synchronisation between AI and Counter

Hi,

I am using NI USB-6353 to measure an analog input signal and counter periods. The two created tasks must start synchronously.

I used this VI as a template and only changed the Encoder Configuration from CI Angular Encoder to CI Period. The problem is, that I always receive error -201314 (Multiple Sample Clock pulses werde deteceted within one period of the input signal). Isn't it possible to synchronize CI Period and an analog input?