User manual
IEC61131 User and Reference Manual
April 22, 2008
91
Modbus/USB
This driver provides the means to communicate with SCADAPack controllers equipped with
a Universal Serial Bus (USB) peripheral port using Modbus/USB messaging. The driver does
not require configuration making it possible to connect and communicate with a SCADAPack
controller almost instantaneously.
To configure a Modbus/USB protocol connection, highlight Modbus/USB in the
Communication Protocols window and click the Configure button. The Modbus/ USB
Configuration window is displayed. The pages in this configuration window are
described in the sections below.
To select a configured Modbus/USB protocol connection, highlight Modbus/ USB in the
Communication Protocols window and click the OK button.
To close the dialog, without making a selection click the Cancel button.
The following sections describe the information presented and user input required to
configure the Modbus/USB driver.
General Page
The general page identifies the type of driver and its author. This page also allows a user to
specify how the application searches and connects to a USB equipped SCADAPack
controller. User input depends on the number of USB equipped controllers connected on the
bus.
Figure 38: Modbus/USB Configuration (General) Dialog Box
The Connection Settings grouping presents two connection options:
Select Automatic Connection when a single controller is present on the bus.
A typical scenario involves a single controller connected directly to a USB port on the host
PC.
The driver will reject connection requests by the application if this mode is selected with
multiple controllers detected on the bus. In this case, the following error message is
displayed: