User manual

IEC61131 User and Reference Manual
April 22, 2008
32
The RTU Station parameter sets the target DNP station number. Valid entries are 0 to
65519. The default address is 1.
The Timeout parameter sets the length of time, in seconds, to wait for a response from the
controller before retrying (see Attempts), or ultimately failing. Valid entries are 1 to 255. The
default is 3.
The Attempts parameter sets number of times to send a command to the controller before
giving up and reporting this failure to the host application. Valid entries are 1 to 20. The
default is 3.
This Serial Port Settings grouping contains details directly related to the PC‟s
communication port including the port number, the baud rate, parity and stop bit settings.
The Port parameter specifies the PC serial port to use. The DNP driver determines what
serial ports are available on the PC and presents these in the drop-down menu list. The
available serial ports list will include any USB to serial converters used on the PC. The
default value is the first existing port found by the driver.
The Baud parameter specifies the baud rate to use for communication. The menu list
displays selections for 300, 600, 1200, 2400, 4800, 9600, 19200, 38400, and 57600. The
default value is 9600.
The Parity parameter specifies the type of parity to use for communication. The menu list
displays selections for none, odd and even parity. The default value is None.
The Stop Bits parameter specifies the number of stop bits to use for communication. The
menu list displays selections for 1 and 2 stop bits. The default value is 1 bit.
The Connection Type parameter specifies the serial connection type. The DNP driver
supports direct serial connection with no flow control, Request-to-send (RTS) and clear-to-
send (CTS) flow control and PSTN dial-up connections. The menu list displays selections
for Direct Connection, RTS/CTS Flow Control and Dial Up Connection. The default selection
is Direct Connection.
 Select Direct Connection for RS-232 for RS-485 connections that do not require the
hardware control lines on the serial ports.
 Select RTS/CTS Flow Control to communicate over radio or leased-line networks
using modems that require RTS/CTS handshaking. Selecting RTS/CTS Flow Control
adds a new tab, Flow Control, to the DNP Configuration dialog. Refer to the Flow
Control Parameters section below for configuration details.
 Select Dial Up Connection to communication over dial up modems. Selecting Dial Up
Connection adds a new tab, Dial Up, to the DNP Configuration dialog. Refer to the Dial
Up Parameters section below for configuration details.
 Click Restore Defaults to restore default values to all fields on this page.
Flow Control Parameters
Flow Control parameters are used to configure how RTS and CTS control is used. When
RTS/CTS Flow Control is selected for Connection Type the Flow Control tab is added to the
DNP Configuration dialog. When the Flow Control tab heading is clicked the Flow Control
dialog is opened as shown below.