I have done more research since my last post and realize that in order to use devices with the same i2c address you need to use an i2c multiplexer. In my case, the PN532 RFID shield from adafruit has a built in address of 0x48. If I want to use two I need to have that multiplexer.
My question stems from not understanding i2c completely. What happens if I hook up both shields without the multiplexer? I don't really care which one reads/writes to a tag. Can I just use the same i2c address for multiple RFID readers and use them as if they were just one giant rfid reader? In the end I just want to have a larger area where a tag could be read in.
Thanks for any information beforehand!