clients can order online by our website. Products selection guide: WJ21 U(A) Input signal(current/voltage) Communication Interface U10-5V A10-1mA 485 RS-485 output interface U20-10V A20-10mA 232 RS-232 output interface U30-75mV A30-20mA U40-2.5V A44-20mA U50-�5V A50-�1mA U60-�10V A60-�10mA U70-�100mV A70-�20mA U8user-defined A8user-defined Products List Samples: WJ21-A4-485 (4-20ma input signal, output is rs485 interface) WJ21-A3-232 (0-20ma input signal,output is rs232 interface) WJ21-A7-485(0-�20mA input,output is rs485 interface) WJ21-A4-232 (4-20ma input signal, output is rs232 interface) Other types,please check our datasheet. Analog Current signal to RS485 or RS232 Converter/Analog data acquisition module.Slim-line plastic housing with integral 35mm DIN rail mounting , power supply(8-32VDC) Features >> Analog signal acquisition,isolated RS-485/232 output >> 12-bit AD converter,testing accuracy>0.1% >> Can Program and calibrate modules accuracy via RS-485/232 interface >> Signal input/output: 3000VDC Isolation >> Wide Power supply:8~32VDC >> High reliability,easy programming,easy installation. >> Can program setting module address,baud rate >> 0-5V/0-10V/0-12V voltage signal or 4-20mA/0-20mA current signal input >> Supports Modbus RTU protocol >> DIN35 Rail-mounted >> Dimension: 106.7x79.0x25.0 mm