RJ45转R485设备有ADDC端口,但..............

RJ45转R485设备有ADDC端口,但用普通的R232转R485接收不了数据,为什么呢?

<span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">ADDC是数据流向自动控制<span lang="EN-US">ADDC </span>（<span lang="EN-US">Automatic Data Direction Control</span>）功能；<span lang="EN-US">RS-485 </span>数据控制<span lang="EN-US">l: ADDC </span>或通过<span lang="EN-US"> RTS</span>控制；内建终端电阻；采用芯片硬件流量控制,但一般的RS232转RS485为什么接收不了数据啊,高手们能帮我解答吗.....................</span>

有没有可以接收ADDC的485转232器啊,求教...................