Three Good Ways To show Your Viewers About Rs485 Cable > 자유게시판

The default serial routines used to download programs to the operating system assume that full duplex communications are available, so you cannot use the RS485 protocol to program the controller. The secondary channel is very useful for debugging application programs that communicate with other computers or I/O via the primary channel. The primary and secondary serial communications ports are accessible through the QScreen's 10 pin, dual row Serial Header (H5) which is typically not installed, the 24 pin, dual row Field Header (H3), and through the individual DB-9 Serial 1 and Serial 2 connectors. The Silence() routine searches the incoming serial characters for a pre-determined keyword (for example, the ascii "name" of this particular slave). Moreover, if Serial2 is running full duplex at 4800 baud, any other interrupt service routine that takes longer than 100 µs is likely to cause a problem. Although the maximum standard baud rate of the primary serial port is 19200 baud, nonstandard baud rates of over 80 Kbaud can be attained by the 68HC11's on-chip UART and the onboard RS232 driver. In this case, cable connections may be made to Serial 2 at pins 4 and 10 of the PDQ Board’s 10-pin Serial Header, or pins 5 and 6 of the Docking Panel’s 10-pin right-angle Serial Header.

The cable can communicate with TER interface of TSX Premium (57), TSX Micro (37), TSX Nano (07), TSX Naza (08) Twido PLC, and to realize the procedures to upload, download, surveillance and other function such as multi-point communication of MODBUS. This helped RS485 become a widely used and very versatile form of serial communication. Since both channels can operate simultaneously and independently, serial debugging can be performed while the application program is communicating via its primary channel. If your application requires RS485, you can use the secondary serial port (serial2) to program and debug your application code using the RS232 protocol, and use the primary serial port (Serial1) for RS485 communications. Connect up a power source (3xAA battery pack, 5VDC wallwart, 7-12VDC wallwart or non-running vehicle power), dial in the program to download and press the Start button. Board lengthened at the power connector end for additional screw down holes. By connecting pairs of these handshaking signals together, the terminal or PC can be made to think that the PDQ Board is always ready to send and receive data. Rather, it relies on software handshaking via transmission of XON/XOFF characters (ascii 0x11 and 0x13, respectively) to coordinate data transfer and ensure that information is not lost when one of the communicating parties is busy.

These protocols are summarized on this page, but for more information regarding their data formats and their use for simplex or multi-drop serial lines, consult Understanding Serial Communications (but keep in mind that that page is directed to the use of the UART Wildcard, so it uses different driver functions). Although the RS232 protocol specifies functions for as many as 25 pins, each communications channel requires only three for simple serial interfaces: /TxD1 (transmit data), /RxD1 (receive data), and DGND (digital ground). RS232’s greatest benefit is its universality; most personal computers can use this protocol to send and receive serial data. The Serial 1 and Serial2 ports can be configured for either RS-232 or RS-485 communications at standard baud rates up to 115200 bits per second. The equipment located along a set of RS-485 wires are interchangeably called nodes, stations or devices. These characteristics make RS-485 useful in industrial control systems and similar applications. The data interface solution is owned by Integrated Sports Systems (ISS) Inc. and is licensed to Water Polo Canada.

The USE.SERIAL2 command means that the operating system’s terminal interface now communicates via Serial2. To provide a convenient means of attaching two grounds to the serial cable, there are several pins (labeled DGND) on the communications connector that are connected to the controller’s ground plane. The wide supply voltage range also means that you can allow for a significant voltage drop along the bus (e.g., when using a bus cable of considerable length). The advantage of using Serial1 for RS485 is that the Serial1 RS485 signals are also available on the Docking Panel, rs485 cable while the Serial2 RS485 signals are available only on the PDQ Board’s Serial Communications Header. From the PDQ Board’s point of view, these three signals (/TxD, /RxD, and ground) are the only connections required to perform serial communications. In this case, cable connections may be made to Serial 2 on either the 10-pin PDQ Board Serial Communications Header, or the Docking Panel’s 10-pin right-angle Serial Header, or the Docking Panel’s Serial2 DB-9 Connector. The transmit and receive data signals carry the messages being communicated between the PDQ Board and the PC or terminal. Contact Mosaic if you require RS485 signals to be routed to the DB-9 Connector.