LubriMist
®
Model IVT
Oil Mist Generating System
Installation and Operating Manual
Page 118
of 256
MODBUS COMMUNICATION
The LubriMist
Model IVT is equipped with a Modbus interface and software to allow for
sophisticated automatic data exchange with a host computer. The interface implements the
standard Modbus protocol originally developed by Gould Modicon and widely used as a control
and monitoring of automated equipment. Additional information on Modbus can be obtained at
the Modbus User’s Webster (www.modbus.org). Detailed specifications for the Modbus protocol
can be found at www.modicon.com/techpubs/toc7.html.
Please note that the information contained in this section is not intended as a Modbus tutorial
(refer to the above sources for such information) but explains in detail only those aspects that are
particular to the IVT Oil Mist Generator. Also, the particular host computer, host computer
software, and transmission medium.
Please also note that the interface software used to communicate with the IVT Oil Mist Generator
in this document uses Modscan, developed and distributed by Win-TECH. Modscan utilizes the
standard Windows Multiple-Document-Interface, (MDI), architecture for displaying Modbus data
to the user. Additional information on Modscan can be obtained at (www.win-tech.com).
The Modbus interface uses the same data communications port described in
Remote
Communication And Alarm
and much of the installation information is applicable.
Overview
The Modbus feature allows the intelligent IVT controller to communicate in a sophisticated and
automatic way with a supervisory or monitoring host computer. Modbus is a “master-slave”
system. The IVT is designed to act as a “slave” with the host computer acting as the “master”.
The host computer is responsible for initiating all communication with the slave. The slave is
responsible for responding to the particular and varied requests sent by the master.
Modbus is a very versatile communication protocol and the IVT implements a very rich set of
Modbus features. All operating conditions of the IVT are available to be read via the Modbus.
The usefulness and overall capability of the Modbus system depends mostly on the particular
host computer and host computer software and the capabilities thereof.
The following sections explain how to install and configure the Modbus feature and how it
implements the particular functions of Modbus.
Installation
Installing and configuring the Modbus feature must follow the steps outlined below and explained
in the sections following.
1. Enable Modbus communication via the dipswitch.
2. Connect the IVT to the host computer through an RS232
RS422/485 converter.
3. Configure the Modbus feature via the IVT control panel.
4. Configure the Modbus software (Modscan) on the host computer.
Serial Data Port – RS-422
The serial communication port can be connected to the serial port of most computers or other
serial Data Communication Equipment. An RS-232
RS-422/485 interface converter is
required to link to the IVT communication port. The RS-232
RS-422/485 interface converter
must be installed in a safe (non-hazardous) location.
It is recommended using (B & B Electronics converter, Model 4WSD9R).
Setup in RS-422 mode,
ECHO OFF,
For a 4 wire or 2 wire configurations.
Refer to figures 1 and 2 below
.
