RS232 to RS485 Converter Cased

RS232 To RS485 Converter Module Cased

Bidirectional Db9 Serial Port Communication Converter Adapter Industrial Automation Control 1200 Meters

     The RS232 to RS485 Converter Cased is a bidirectional data converter that connects the DB9 RS232 serial port of a computer or a device to a 2 wire RS485 line. One end has a DB9 female connector with fixing screws, the other end has a 4 pin screw terminal labelled 485+, 485-, GND and +5-12V. Thanks to its black plastic case it is not left unprotected like a bare circuit board; it plugs directly into the COM port and is fixed with its screws.

     While the cable on the RS232 side of the converter can be at most 5 meters, the RS485 line reaches up to 1200 meters with twisted pair cable, and up to 32 devices can communicate on the same two wires. It works asynchronously in half duplex mode and supports speeds between 300bps - 115.2Kbps. It is therefore used to read and configure PLCs, inverters, energy analyzers, meters, thermostats and other Modbus RTU devices from a computer.

     An external DC 5V-12V supply can be applied through the +5-12V and GND inputs on the terminal side. With dimensions of 55mm x 33mm x 17mm and a weight of 22gr it takes little space in a panel or behind a serial port.

Key features:

     Cased and screw fixed: The circuit is inside a black plastic case; the fixing screws on both sides of the DB9 connector hold the converter firmly on the COM port, it does not loosen under vibration.

     Solderless terminal connection: The RS485 line is connected with a screwdriver to the 4 pin screw terminal (485+, 485-, GND, +5-12V); no extra connector or soldering is needed.

     Line up to 1200 meters: It overcomes the 5 meter cable limit of the RS232 side; on the RS485 side devices up to 1200 meters away are reached with twisted pair cable.

     32 devices on one line: Up to 32 devices can be connected to the same 2 wire RS485 line; meters, analyzers and drives addressed with Modbus RTU are read from a single port.

     No driver needed: The converter works at hardware level; the computer uses it as a normal COM port, no software installation is needed.

Features:

• Product type: Cased RS232 - RS485 bidirectional serial communication converter
• Model: RS232 to RS485 Converter Cased
• Standard: Compatible with EIA/TIA RS232 and RS485
• RS232 side: DB9 female connector, fixing screw on both sides
• RS485 side: 4 pin screw terminal: 485+ (A), 485- (B), GND, +5-12V
• External supply input: DC 5V-12V (+5-12V and GND pins on the terminal)
• Operating mode: Asynchronous, half duplex
• Transmission line: 2 wire (485+ / 485-), twisted pair cable recommended
• Communication speed: 300bps - 115.2Kbps
• RS485 line distance: up to 1200 meters
• RS232 cable distance: up to 5 meters
• Devices on the line: up to 32 devices
• Protocol: Protocol independent; passes Modbus RTU and similar serial protocols
• Driver: Not needed, works through a standard COM port on the computer
• Operating temperature: -10°C - 85°C
• Material: Plastic case, metal DB9 connector
• Color: Black case, green terminal block
• Dimensions: 55mm x 33mm x 17mm
• Weight: 22gr

Usage information:

• Plug the DB9 female end into the DB9 male RS232 port of the computer or device and tighten the screws on both sides. If your computer has no COM port, use a USB - RS232 converter cable.
• Connect the 485+ terminal to the A (D+) pin of all devices on the line and the 485- terminal to the B (D-) pin; also join the GND pins of the devices at the GND terminal. If a device does not respond, try swapping the A and B wires; some manufacturers use the labels the other way round.
• Converters of this type usually take their supply from the signal lines of the RS232 port (RTS, DTR, TXD). If the port power is not enough (some laptops and USB - RS232 converters), apply an external DC 5V-12V supply through the +5-12V and GND terminals.
• Use twisted pair cable on long lines; using a 120ohm termination resistor at the devices on both ends of the line reduces reflections.
• In the serial port program on the computer set the speed, data bits, parity and stop bits the same as the device you communicate with.

Applications:

•  Programming and monitoring PLC devices from a computer
•  Configuring inverters and motor drives with Modbus RTU
•  Reading energy analyzers and electricity meters
•  Collective reading of water, gas and heat meters
•  Reading data from weighing scale indicators
•  PTZ camera (Pelco-D / Pelco-P) pan and zoom control
•  Remote setting of thermostats and temperature controllers
•  Access control and turnstile systems
•  LED signs and scrolling message boards
•  Computer connection in SCADA and data acquisition systems

Things to consider:

•  This converter needs RS232 level signals. It cannot be connected directly to the 3.3V / 5V TTL UART pins of a microcontroller; a TTL - RS485 module is needed for a TTL output.
•  The RS485 side is 2 wire and half duplex; only one device sends data at a time. It is not suitable for 4 wire full duplex RS422 lines.
•  Do not apply more than 12V to the +5-12V input and do not reverse the supply polarity.
•  No isolation rating is given for this product. On long outdoor lines with large ground differences or lightning risk, prefer an isolated converter and a surge protector.
•  All devices on the line must use the same speed and different addresses; two devices with the same address disturb the communication.

Package contents:

•  1 Piece RS232 to RS485 Converter Cased
•  Note: RS232 / USB cable, RS485 line cable and external power adapter are not included in the package.