The reason you are seeing the resource is reserved error is because there is only one analog input timing engine for acquisition tasks. So, you need to have all the channels you are acquiring from in the same task (same as an E or M series DAQ card). I attached a screenshot of how to set this up (I used the code you supplied). Also, the link below discusses the analog input timing restriction in more detail.
Specifying Different Sample Rates for Multiple CompactDAQ Modules