The board can accept differential encoder signals when an extra-cost option is installed. When this option is installed, jumpers can select from differential or single ended receivers on an encoder-by-encoder basis. (In fact, even the individual signals for one encoder can be selected this way, although such a use would be rare.)
Additional logic is provided to read an index or zero reference channel along with the encoder quadrature signals. This signal sets a register bit when a low-to-high transition is detected.
There is a 24-bit preset register that can be used to preset one (or all) counters to a specific value.