Hello Al,
If you want a pressure reading for each pulse of the encoder, all you have to do is use your encoder output A (provided its a TTL pulse train) as the clock source of a continuous analog input acquisition. Look for analog input examples that use an external clock source. Since it sounds like you also want to count the encoder pulses, your encoder output A will end up being connected to both a counter input and the AI clock source pin. You will have two separate measurements running, one being a counter measurement and the other being an analog input measurement. They can run simultaneously.
Regards,
Doug Norman