How to Configure Modbus Shared Variable for Float Value in Single Shared Variable

This article will demonstrate on how to configure Modbus shared variable for float value in single shared variable in LabVIEW.

If you wish to use in single shared variable to display as float value, you may create the variable under F3xxxxx or F4xxxxx.

1. In LabVIEW project right click the Modbus library and select Creating Bound Variables...
2. Select Add range >> to add require number of data items.

3. Select the starting address and the range. In this example we add 2 data items to represent one float value.

4. Click OK to add the shared variable in the project. In this example, we are using F403059 and F403060 to represent float (32-bit) or SGL in LabVIEW.

5. Both F403059 and F403060 shared variables will show under the library. 

6. You only require to pull in one shared variable and it will represent as float or SGL value as shown below. However, take note that the F403059 in this example is a float 32-bit which will occupies Modbus Holding Registers at address 3059 and 3060 as each address has 16-bit. User should aware that Holding Registers at address 3059 and 3060 is already being used by F403059. Address 3059 and 3060 must not be calling read or write for another variable at Holding Registers as it has been reserved.