Noise monitors RS485 output interface

RS485 output interface known as noise monitor SLM (Sound Level Meter) is the most basic noise measurement instruments. Sound level generally consists of a condenser microphone, preamplifier, attenuators, amplifiers, frequency weighting network and RMS indication table top components. Our sound level meter on the basis of the development of new products and noise monitors in addition to the basic functions, is increasing output, on-line monitoring, etc. Based on this characteristic. Noise monitor output: 1. RS485 serial port is an interface standard, which defines the electrical standard interface, it simply just a standard physical layer. Interface card does not require cables and protocols used, so long as the interface plug-in cable we use comply with the standard serial port can be used flexibly in practice, using a variety of protocols for communication and device control on a serial interface standard. 2. RS232 RS232 interface is a standard for serial communications in 1970 by the American Electronics Industry Association (EIA) Joint Bell System, a modem manufacturers and computer terminals manufacturers jointly developed. Its full name is "serial binary data exchange interface between technical standards for data terminal equipment (DTE) and Data Communications Equipment (DCE)". The standard specifies the use of a 25-pin DB25 connector, to be provided for each pin connector signal content, but also to provide for the level of various signals. With the continuous improvement of equipment, there has been in place DB25 DB9 connector, now regarded RS232 interface called the DB9. 3. 4-20mA instrumentation signal current general are 4-20mA, refers to the minimum current of 4mA, a maximum current of 20mA. When a transmission signal, taking into account also the wire resistance, if it will drop some voltage transmission wires generated signals that the receiver will produce some error it! So using a current signal as the standard transmission transmitter! 4. 0.3-1.3V make on-site noise signal without distortion to 0.3 ~ 1.3V voltage output, directly supporting the use of the user's PLC