LubriMist
®
Model JD
Oil Mist Generating System
Installation and Operating Manual
Page 78 of 152
MODBUS COMMUNICATION
The LubriMist
Model JD 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 JD 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 JD 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 JD controller to communicate in a sophisticated and automatic way
with a supervisory or monitoring host computer. Modbus is a “master-slave” system. The JD 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 JD implements a very rich set of Modbus
features. All operating conditions of the JD 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 JD to the host computer through an RS232
RS422/485 converter.
3. Configure the Modbus feature via the JD 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 JD
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
.