Industrial Serial RS232 RS485 RS422 to Fiber Converter Bidirectional High Speed Optic Modem SFP Slot Serial Over Fiber Converter

Typical with serial connections, I had to do some trial and error to get this working. Used this to connect an access control panel which requires 4 wire RS485 over a fiber connection. Used 2 per panel. Instructions were backward about the LEDs, and the labeling is confusing if using 4 wire 485 because it doesn't have TX+, RX+, TX- & RX-. Sent email to support and they sent a picture of how to hookup for 4 wire RS485, and it worked. However the manual says the LEDs should be solid when connected correctly, but in reality, they should be blinking, I believe. Whatever manula said was opposite of how it worked. I sent them another email letting them know the manual was incorrect, in hopes they would correct it. I'm ordering more, so we'll see.