Multiple RFID with RS485 communication

I wanted to connect multiple RFID readers(8 readers) to my Arduino. I read that their can issues when connecting higher number of RFIDs to Arduino. I researched on RS485 communication which can be use for multi-point drop, But i don't have a clear idea on connecting all these RFIDs to Arduino using RS485. If someone can explain it will be great help.

If the reader outputs RS232 or serial TTL then RS485 is not a suitable protocol for this, as there is no buffer between the tag information and the poling of the RS485 devices.