2001 tach signal source?

On an '01, does the tach run off the CPS in the distributor hole? Is there another "CPS" on the bellhousing on mine?
I was told I had a CRANK position sensor AND a CAM position sensor. This doesn't make sense to me, since the cam and crank are hooked together by the timing chain.
Please fill me in....
TIA! :wave1:

They all have both a crank position sensor and a cam position sensor. However, I don't know what triggers the tach in the OBD-II models.