modbus - HELP for final exam

[Torassa]

Good morning.
We are two students of a technical institute who are attending the last year and as a topic of dissertation for the " state exam " are using language with Labview Modbus . The purpose of this experience is to be able to carry through a program run with Modbus and Labview , monitoring of the photovoltaic devices via 3 "SLAVE" ZR- TIDCI - OPT1 -EM and a "MASTER" ZC -GW -ETH -EM . We started trying to understand the various library functions NI Labview Modbus present in starting and helping with the examples already set in the program and then process them. We were able to set the various elements, such as the IP address of the MASTER , the IDs of the slave etc. . , But after several steps we are stuck because of an "ERROR 63 occurred at TCP Open Connection" .
The error is present in the block " TCP Write " in the " MB Ethernet Transmit" .

A possible cause of the problem could be the "transaction ID " ?
Some might auitarci ?
The exam is near ...

[Cla_Cup]

Hi all,

did you try to run the ModBUS TCP (Master/Slave) Examples? They are very simple and are good starting points for developing more complex applications.

Download the modbus_library here. You'll find the above example in the .llb you'll download.

Anyway the error 63 come from a wrong TCP setting (IP Address or Communication port). Check if the communciation port is not currently used by other processes or try to change it. Try to run master and slave examples on the same machine with "localhost" as IP address.

In the following there are some Modbus error related links:

What Are the Most Common VI Server Errors?

How Do I Use Remote VI Server Over the Network?

Introduction to Modbus

I hope that these informations will help you with your exam preparation.

GOOD LUCK and best regards.

Cla_CUP

NI ITLAY

AE Dept.