Modbus TCP Polling

[Chad-TQ]

Hi all

I am trying to create a VI that allows me to monitor modbus polls over TCP. The slave device is a Elpro 245U-E Ethernet modem. I can succesfully read x amount of registers using a program called Modscan as seen below. 

I want to recreate something similar to this in Labview. All im interested in is the number of polls and the poll responces. 

I am using Labview 12.0 on Win7. I have used the modbus library previously to create a few VIs. I cannot find an example there that would help me do this.

Are there any examples available else where? any help would be appreciated.

Regards,

Chad

[thibber]

Hi Chad-TQ

I'm not sure that there is a program we have that simply monitors the bus for requests and responses without writing anything explicitly itself.  I know that you would certainly be able to use a counter to keep track of the Modbus Reads and Writes that you perform in your program, if that is what you are trying to do.  However, access to all Modbus traffic from any source to any register is information that I do not think you will be able to access.

You could try posting this question to the Industrial Communications Forum linked below:

http://forums.ni.com/t5/Industrial-Communications/bd-p/260

Someone there might have a better idea of a strange workaround that could get you the information you need.

[nonecure]

Just follow my example code in this thread.  You will need to send a read of address 1 just like your modscan is doing.

http://forums.ni.com/t5/LabVIEW/Kollmorgen-AKD-communication-with-Labview-Ethernet-IP-drivers/td-p/2...

[Chad-TQ]

Thanks guys, will give it a try.