How to transfer Allen bradley Compactlogix PLC`s TAG to Modbus TCP/IP

Dear all,

I would like to transfer the Compactlogic PLC information (TAG), to Modbus TCP/IP. I come across this Prosoft module MVI69-MNET could perform the function. However, i have not idea of how to write the program to periodically tranfer all the TAG , to be available for modbus TCP/IP information transfer to my client`s scada system. As Allen bradley infomration is available on the TAG inself, does not have the address. I appreciate if someone have the knowledge could help to share with me.

Best regards,
mixguy

Welcome to the Forum!

As part of the setup of the MVI69-MNET, you have to define your Input and Output Mapping. You should also have have created some Data Files and PLC Code to support the MNET Card.

Normally there is a MNET.DATA Tag with Sub-Tags Read and Write. That is where you would copy your Data from and to respectively.

Have you used Configuration Builder to set up your MNET Card?

Have you created the Data Files and PLC Code to support it?

Is the MNET Card set up as Master/Client or Server/Slave?

http://www.prosoft-technology.com/content/view/full/6458

Stu....

Stu..

Basically, this Prosoft MVI69-MNET is new thing to me. I hope i can get a guidances step by step to setup the MVI69-MNET and how link the compactlogix TAG to this module.

I have not done anything yet, as i just bought the hardware, and still figuring of how and where to start.

In my compactlogix all of my data are in form of TAG. For example, The temperature reading of an oil tank, i assigned it as "OilTankTemperature" in the compactlogix TAG. As this TAG is not in the form of address. How to link it to MVI69-MNET?

Mixguy

You would move it to the appropriate location in MNET.DATA.WriteData. The exact location is decided by the MVI69-MNET Configuration.

Follow the Link in my previous Post, and Download the Manual, Sample Ladder, and Configuration Builder. Read through the Manual on how to set it up.

You need to Configure the MNET Card, and add Ladder Logic or an AOI to support the MNET Data Transfer to and from the PLC.

You have to know/decide if the MNET is going to be the Master/Client or the Server/Slave on Modbus. In most cases it will be a Client, but it depends on your circumstances.

Stu....

The MNET will be the point where all the PLC information is available to be read from My customer plant`s SCADA system. In this case, is the MNET is as a "Client" ? As the communication is via Modbus TCP/IP from the SCADA system to read the information available at MNET.

I am not really understand about Master/Client and Serve Slave on Modbus, I appreciate more clarification to clear my understanding.
Thanks

Mixguy

In the case you quoted, your MNET would be a Server/Slave to the SCADA which would be the Client/Master.

The Modbus specifications call for one unit to be a the Client/Master that Polls the Server/Slave.

Some reading for you on Modbus.

http://www.modbus.org/specs.php

Stu....

Just a side note..
For modbus RTU, 1769-SM2 module can also be used. It's a lot cheaper and relatively easy to set up.

Offset address - MNET as Slave

hi all,

i've problem with MVI69-MNET. in my project MNET is slave. My client have their standardize modbus address that i've to follow which means I have to configure the address based on their database. my problem is i don't know how to offset the address as the address given range is from 47000 till 49000. from my understanding MNET address is from 40000 to 44999.

FYI, i've no problem configuring MNET as Master as I offset the address using the PCB "MNET Client Command"