Our current generation of pcProx plus model readers will support 4 card configurations.  Our older generation does not.  The easiest way to determine if your reader will support 4 configurations or not is to look at the label on the back of the reader and check the firmware. If your firmware begins with PLC it will only support 2 configurations. If your firmware begins with LNC it supports 4 configurations. 

*please note PLC readers cannot be updated to LNC firmware to support 4 configurations.  The new firmware and new card abilities are due to newer hardware within the reader.