There are no existing objects in Niagara G3 that can split a 16-bit Modbus register into two 8-bit values with one representing the high byte (bits 8-15) and another the low byte (bits 0-7).
Niagara G3 all versions
Modbus integration of a 3rd-party product using 16-bit values which must be split into two 8-bit values.
A program object is available below that will achieve this requirement. The output of this object generates two 8-bit integer values and two string values for use with logic programming and display purposes.
Text file of program code