Allen-Bradley 1420-V1, User Manual, Page: 45 / 90

Rockwell Automation Publication 1420-UM001E-EN-P - March 2016 45
Communication Chapter 4
Modbus Register Format
Modbus registers are 16-bit words that are organized as shown in the following
diagram.
32-bit and 64-bit Data types that are presented as arrays of single registers in
LSW (least significant word) to MSW (most significant word) order.
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
MSb (Most Significant Bit) (Least Significant Bit) LSb
High Byte (MSB) Low Byte (LSB)
Holding Register (word)