RS232-LVTTL from a RFID reader

I’m trying to read serial from this module by Feig. Originally I thought that this was an RS232 device, so I bought a MAX3232 converter off Sparkfun to shift those levels to something I could read on the Arduino serial port-- but I’m not getting any data transmitted, even though the “read” light illuminates on the module to show the data is being transferred.

I see that the datasheet is listing RS232-LVTTL as an option, and it seems that this might be what I have. If so, what does this mean exactly, and how can I read it into an Arduino Serial port?

For those interested in details, I measured voltage on the wire that currently goes from the TX on the RFID module to the MAX3232, and it seems to be reporting a steady 2.3V (relative to a common ground). I currently have the MAX3232 powered by a the 3.3V from the Arduino, the RFID powered from the 5V from the Arduino, and everything tied to a common ground. I am using a MEGA where the default Serial class is being used to echo to the computer, and Serial1 is trying to read the RFID module. I have attached a more detailed hookup guide for this RFID Module as well.

Installation Manual MU02.02_4e.pdf (796 KB)

Which one exactly do you have? The datasheet mentions an -AD and a -CU version. Which one do you own? Does your’s have a USB interface?

Post a wiring diagram of your setup!