If more encoder inputs are required in the same spot of a CMM, it is possible to use a double axis board. They are similar to the single axis boards but use a single, more performant, DSP capable of reading two axes. The advantages of using this board instead of two single axis boards, are the reduced space and power required, along with a lower price.

If using open encoders and double reading heads to further enhance the accuracy of the transducer, the double axis boards become a must.