Serial Parameters

Name of the Connection

You can choose any connection name you like. All characters except brackets may be used.

Connection Active

Shows whether the connection is active or not. If not, you cannot register items and there will be no connection to the PLC. This feature allows you to disable a connection temporarily without deleting it so that you can re-enable it later without having to enter all parameters again.

Write allowed

For some connections, you can disable the Write function.

Line

Shows the selected serial interface. It is possible to choose the line with the drop box.

Baud Rate

The baud rate (also referred to as modulation rate) indicates the number of state changes in the transmitted signal per second. You can set baud rates from 75 to 115200. The same baud rate must be used for the sending and the receiving stations.

Data Bits

Indicate the number of bits per character here: 5, 6, 7 or 8

Parity

The same parity must be used for the sending and the receiving stations.

Even

For even parity, the number of 1s (including the parity bit) is even.

Odd

For odd parity, the parity bit is set in a way to obtain an odd number of 1s (including the parity bit).

None

Select this option if you do not want to use the parity check.

Mark

Select this option if you want the parity bit to be permanently 1, i.e. if your device expects a 1 parity bit.

Space

Select this option if you want the parity bit to be permanently 0, i.e. if your device expects a 0 parity bit.

Stop Bits

Duration of the stop bit transmission, relative to the transmission time of an information bit. For asynchronous, serial lines, the transmission of a character is terminated by sending a stop bit. Specify here whether 1 or 2 bits will be used for termination.

Handshake Protocol

Here, you can select the protocol mode to be used. The devices use it to communicate whether they are ready to send / receive data. There are two types of handshake: software handshake and hardware handshake.

Hardware handshake means that synchronization is done via electrical wires. V.24 typically uses either RTS / CTS or DTR / DSR for signaling.

Software handshake means that synchronization is done by transmitting control characters. XON / XOFF are the most common software handshake characters.

RTS / CTS

RTS= Request To Send, signal of the V.24 interface

CTS= Clear To Send, signal of the V.24 interface

DTR / DSR

DTR= Data Terminal Ready (to send), signal of the V.24 interface

DSR= Data Set Ready (for operation), signal of the V.24 interface

XON / XOFF

The communication partners add ASCII characters to the communication data stream. These control characters in the data stream indicate whether the data flow is possible or not:

XON: data can be received

XOFF: data cannot be received

RS485

Select RS485 if the serial device is connected to the echo device via an RS485 cable.

DTR RTS = 1

Select DTR RTS = 1 if DTR or RTS default to 1

None

Select None if you do not want to use any of the protocols listed above for the serial line.

Timeout

This option specifies the time after which the device will no longer wait for a response and assume the partner is not present.