How to Configure LabVIEW to Communicate with Modbus I/O Modules Via an OPC Server – 8500881

Configuring LabVIEW 2009 to Communicate with Acromag BusWorks and EtherStax Modbus I/O Modules via an OPC Server

Introduction

National Instruments™ LabVIEW can be used to monitor and control Acromag BusWorks ® and EtherStax ® Modbus I/O modules via an OPC server. A separate application note, Configuring Kepware KEPServerEX® 5.0 for communications with Acromag BusWorks and EtherStax Modbus I/O Modules, outlines configuration of a KEPServerEX OPC server. This document focuses on setting up controls and indicators in LabVIEW to read and write the OPC server tag data.

The following hardware and software were used in the creation of this document:
• Microsoft Windows® XP Professional – Service Pack 3
• LabVIEW 9
• Kepware KEPServerEX (version V5.0.1176.0 – U) with Modicon Modbus Driver Suite
• Acromag Model ES2152 16/16 Channel DC Voltage/Current Input (Modbus TCP/IP)

Note that this document does not cover the DCOM and firewall configuration settings required to allow remote clients to connect to the server. Good sources of information on this topic are the Kepware and OPC Foundation websites.

LabVIEW Client Example

The following example will create a simple LabVIEW application that will communicate with an Acromag ES2152. The front panel of the application will have an indicator to read an input
voltage.

The OPC server was previously configured with two tags corresponding to the input voltage represented as float value and as an integer value:

 

 

 

Download PDF for complete application note.