NEW RS232 to RS485 1.2KM Data Interface Adapter Converter diy electronics

Specification:
   1,Data Transfer Rate: 300-115200bps
   2,Operating Distance: 1200m for RS485, 5m for RS232
   3,Power: None required, uses TD as power source
   4,Environment: -10C to 85C, 5% to 95% RH
   5,Interface: Compatible with EIA/TIA RS-232C standard and RS-485 standard.
   6,Working mode: Asynchronous, half-duplex, differential transmission.
   7,T-ransmission media: Twisted-pair or shielded twisted pair (STP).

   With this item,it is easy to add an RS-485 interface to a PC via RS-232.
   This does not need any AC or DC power.
   It uses a particular pump to gain power from RS-232 signal (RTS, DTR, TXD) without initializing the RS-232 series interface.