Some sub-VI's require Modbus communication to work properly. Without the Modbus library, some sub-VI's will become unusable. The Modbus Library used in this code can be found here: http://forums.ni.com/t5/NI-Labs-Toolkits/LabVIEW-Modbus-API/ta-p/3524019 (Direct download link = http://forums.ni.com/ni/attachments/ni/7324/526/6/ni_lib_modbus_library-1.1.5.39.vip), and is also included in the BASIS drivers Zip file available on our website. This Modbus library requires LabVIEW 2012 or later. Change Log: Driver library version 2.1.1: -All sub-VI's were completely overhauled from version 1 to version 2 to include more features, easier access to data and setpoints, and added functionality. -Modbus library included to enable additional functionality. -The example program included is now a fully functioning interactive multi-unit driver. -A bug with Windows regional settings for the decimal (period vs comma) was fixed, and the code should now work properly with either regional settings.