TRB142 RS232

Summary

The RS232 function is designed to utilize the serial interface of the device. Serial interfaces provide a possibility for legacy devices to gain access to IP networks. This chapter is an overview of the RS232 section.

RS232 Configuration

The RS232 Configuration section is used to configure the parameters of the RS232 serial connection. Parameters used should be selected in accordance with the needs of the user and the type of device connected via the RS232 port.

The figure below is an example of the RS232 Configuration section and the table below provides information on the fields contained in that section:

field name	value	description
Enabled	yes | no; Default: no	Enables the RS232 service
Baud rate	300 | 1200 | 2400 | 4800 | 9600 | 19200 | 38400 | 57600 | 115200; Default: 115200	Data rate for serial data transmission (in bits per second)
Data bits	5 | 6 | 7 | 8; Default: 8	Number of data bits for each character
Parity	None | Odd | Even; Default: None	In serial transmission, parity is a method of detecting errors. An extra data bit is sent with each data character, arranged so that the number of 1 bits in each character, including the parity bit, is always odd or always even. If a byte is received with the wrong number of 1s, then it must have been corrupted. However, an even number of errors can pass the parity check. None (N) - no parity method is used Odd (O) - the parity bit is set so that the number of "logical ones (1s)" has to be odd Even (E) - the parity bit is set so that the number of "logical ones (1s)" has to be even
Stop bits	1 | 2; Default: 1	Stop bits sent at the end of every character allow the receiving signal hardware to detect the end of a character and to resynchronise with the character stream. Electronic devices usually use one stop bit. Two stop bits are required if slow electromechanical devices are used
Flow control	None | RTS/CTS | Xon/Xoff; Default: None	In many circumstances a transmitter might be able to send data faster than the receiver is able to process it. To cope with this, serial lines often incorporate a "handshaking" method, usually distinguished between hardware and software handshaking. RTS/CTS - hardware handshaking. RTS and CTS are turned OFF and ON from alternate ends to control data flow, for instance when a buffer is almost full Xon/Xoff - software handshaking. The Xon and Xoff characters are sent by the receiver to the sender to control when the sender will send data, i.e., these characters go in the opposite direction to the data being sent. The circuit starts in the "sending allowed" state. When the receiver's buffers approach capacity, the receiver sends the Xoff character to tell the sender to stop sending data. Later, after the receiver has emptied its buffers, it sends an Xon character to tell the sender to resume transmission
Serial type	Console | Over IP | Modem | Modbus gateway | NTRIP client; Default: Console	Serial connection type. More information on each serial type can be seen below or by clicking on a link in the value section
Echo	yes | no; Default: no	Toggles RS232 echo ON or OFF. RS232 echo is a loopback test usually used to check whether the RS232 cable is working properly

FIELD NAME	VALUE	DESCRIPTION
Enabled	yes | no; Default: no	When checked, enables the RS232 service
Baud rate	300 | 1200 | 2400 | 4800 | 9600 | 19200 | 38400 | 57600 | 115200; Default: 115200	Sets the data rate for serial data transmission (in bits per second)
Data bits	5 | 6 | 7 | 8; Default: 8	The number of data bits for each character
Parity	None | Odd | Even; Default: None	In serial transmission, parity is a method of detecting errors. An extra data bit is sent with each data character, arranged so that the number of 1 bits in each character, including the parity bit, is always odd or always even. If a byte is received with the wrong number of 1s, then it must have been corrupted. However, an even number of errors can pass the parity check. None (N) - no parity method is used Odd (O) - the parity bit is set in a way that the number of "logical ones (1s)" has to be odd Even (E) - the parity bit is set in a way that the number of "logical ones (1s)" has to be even
Stop bits	1 | 2; Default: 1
Flow control	None | RTS/CTS | Xon/Xoff; Default: None
Serial type	Console | Over IP | Modem | Modbus gateway | NTRIP client; Default: Console	Specifies the serial connection type.
Echo	yes | no; Default: no

FIELD NAME	VALUE	DESCRIPTION