This MJ20-PRG module clicks in the PLC and provides one RJ11 socket for serial communications with a PC. This provides high noise immunity and allows distances up to 4,000 ft (1200 meters). This cable provides a USB type A connector for the PC end and an RJ11 connector for the meter end. Normally pin 7 (RTS) and pin 4 (DTR) are used on the DB9 connector. Note that these cables are different from4-wire telephone cables or crossover cables. What RJ11 cables should I use with RS485? Should I use RJ11 or RJ45 connectors? The RJ11 socket is interesting, because the manufacturer choose to have a symmetrical pin-layout, rs485 cable just as with the MMJ connector on DECconnect systems and the RJ45 jack in the Yost standard. These ports use an RJ11 socket as physical connector. You can easily connect more devices by splitting the cable at one connector and adding another cable to it.

More pricey than N-channel as the P-MOSFETs and TPIC6C595 shift registers cost more. Uno shield, shift register controlled by any 3 pins. Easy to use - just shift in 4 bytes, a 1 turns an output on to source current from the NDP6020P . Use Laurel’s 6-wire data cables CBL03-1 (1 ft) and CBL03-7 (7 ft) to interconnect meters if these lengths fit your application. This means that when RS485 is used in a 4-wire application and the transmit and receive circuits are thus separated that you can add up to 64 devices on a segment. RS-422 and RS-485 Standards Overview and System Configurations, Application Report (pdf). The diagram below shows potentials of the A (blue) and B (red) pins of an RS-485 line during transmission of one byte (0xD3, least significant bit first) of data using an asynchronous start-stop method. However since only a true RS485 network can have addressable serial RS485 devices, the RS232 converter needs to be addressable either by software or by DIP switches when using it in this type of configuration. The advantage of the RS485 protocol is that this it can transfer data over longer distances, up to 4000 feet, and have up to 32 nodes per single network, and it can be used for multi-point networks where multiple serial devices are setup in a bus network.

Xwire protocol over RS485 will allow cable runs of up to 1km - with suitable cable and grounding precautions- and up to 32 devices. Some of these converters can convert from RS232 to both RS485 and RS422 however many standard models only has one of the protocols. The serial RS232 to RS485 converter and RS232 to RS422 converter units, also called serial converters, are small electronic devices used to convert a serial RS232 signal, (for example the COM port in older computers) into either RS485 or RS422 signals. These signals are commonly called A and B in RS485 systems. These pins are normally used for the DTR, data terminal ready and DSR, data set ready signals. RS-485 signals are used in a wide range of computer and automation systems. Although many applications use RS-485 signal levels, the speed, format, and protocol of the data transmission are not specified by RS-485. A RS232 - RS485 converter is often used in industrial data acquisition and control applications where multiple serial devices communicate with each other through a converter. It is also used in Digital Command Control (DCC) for model railways.

Display and configure video; control PTZ; test cables, audio, IP network connections, PoE voltage; and power 12VDC cameras. The TESTER-CCTVPOE-P Professional CCTV Tester with Power Over Ethernet (PoE) and IP Testing is a portable, multifunction tester for CCTV installations and maintenance. This is a method for connecting multiple RS485 devices with each other over a two-wire network. The RS485 converter interface uses two wires for communication, one for transmitting and one for receiving data, which is referred to as a half-duplex communication converter. Both boards support the Modbus protocol and Laurel’s Custom ASCII protocol, as well as half-duplex or full-duplex RS485 communications. The RS485 interface allows the creation of multi-point networks. 2) the GSM version also allows you to indicate a possible PIN (leave blank if there is no PIN) and the operator's APN (possibly you can search for it on Google). The symmetrical pin layout of the RJ11 sockets on the Unitronics PLCs allows an easy way of interconnecting the PLCs with both RS232 and RS485 communications. RS485 is a balanced serial interface for the transmission of digital data.