Yes, you can add a second keypad to operate the same door. It can be any of the following keypads. DK-26PBK (narrow black - indoor/outdoor), DK-26PSS (narrow stainless steel - indoor/outdoor) or DK-16P (single gang - indoor).
No, we do not offer a weatherized version of the DK-11, but we do offer the WCC single gang weather cover and the WBB weather back box for the DK-11. The WCC and WBB will offer protection for the DK-11 when used outdoors; however, it still should not be used where it would receive direct rainfall. A caution should be noted here. The temperature range of the DK-11 is only operable down to +32 degrees F. If you have temperatures that drop below that range then do not use the DK-11 outdoors. A second concern would be the actual security of the keypad. The DK-11 is meant for lower security applications. Certain attacks on the DK-11 could cause the portal to open. Overall the DK-26 is a better choice for outdoor applications.
Wiegand Output version has no built-in code capacity. The Wiegand Output version is meant to attach to the Wiegard card reader input of most card access control manufacturer's reader panels. Actual code capacity would be determined by the software/hardware configuration of the access control system.
Yes, we offer the DK-CPSS cover plate for this very application. It is drilled to mount to single gang box and cover the opening while still providing a mounting plate for the DK-26 keypad. The DK-CPSS is available on in the stainless steel finish and is approximately 3" X 8" in size.
No, usually you will need to provide separate power for the keypad system. If the strike has a large enough in-rush current to max out the transformer, the keypad system will crash. An inexpensive plug-in D/C power supply would suffice, such as Securitron part # PSP-12 or PSP-24.