blackboxIC821A型号：IC821A产品描述:UniversalRS-232toRS-422/485ConverterwithOpto-IsolationFurtherDetailsTheBLACKBOX?UniversalRS-232?RS-422/485ConverterwithOpto-IsolationisolatesandconvertsRS-232signalsintoRS-422/RS-485signalsandviceversa.Unlikeotherconverters,externalsoftwareisnotrequiredtocontroldataflow.TheRS-232inputiswiredforDCEthroughaDB9femaleconnector,andRS-422/RS-485signalsareinterfacedthrougharemovableterminalblock.Tosupplyexternalpowertotheterminalblock,youneedour120-VAC/12-VDCWallmountPowerSupply(PS1003).ForRS-232,theconnectionrequiresRD,TD,andSignalGround.InRS-422mode,thedriverisalwaysenabledforfull-duplexcommunicati***.Atwistedpairisrequiredfortran***it,andatwistedpairisalsorequiredforreceive.Agroundreferencewireisalsoneeded.SwitchsettingsareSwitch1:RS-422;Switch2:EchoOn;Switches3and4:4Wire.)