The HID ProxPro® proximity readers are available with an optional key pad. The key pad has twelve keys (four rows by three columns), like a common telephone key pad. The Internal method sends the key pad data on the same data lines as the card data. The ProxPro 5355 carries card and key pad data across the wiegand lines. The ProxPro 5352 carries card and key pad data across the serial lines. Set Dip Switch SW1-4 to the on position for selecting the Internal mode. This switch group is located in the lower right corner of the ProxPro circuit board.