Realtime viewing and logging multiple MODBUS slave device register values

[methane]

Our lab expert left and I need help obtaining data from two slave devices communicating via modbus protocol through RS485 to USB. I would like to connect them to LabVIEW to visualize and log data on these flowmeters (Endress Hauser CNGnass MODBUS RS485, read address 32007)

I've been trying to use the Modbus library without success and do not have access to the DSC module. I only want to read the register values for these two separate (USB connected) devices, see what is going on live to know when to shut them down in LabVIEW, and then have a file export where I can do further analysis of the data. 

How do you configure two separate USB MODBUS devices, get a live read of their values with a single graph, and save both sets of data to a timestamped file with time on X axis and both device data on Y.

I've attached my attempt for this, please let me know if you have any suggestions

[PatrickLye]

When programming to Modbus I've used a free program called WireShark to diagnose packet problems on Modbus TCP. You might look at this program to see if it will help you figure out the problem on Modbus RTU.

I have a project that will begin soon on Modbus RTU. I may be able to help out then since I also will be moving away from the DSC module for that project to see how it works out.

[methane]

Have you seen any VIs that log multiple COM Serial Modbus devices?