262 Rockwell Automation Publication 2080-UM002N-EN-E - November 2022
Appendix A          Modbus Mapping for Micro800
NOTE: Strings are not supported. 
In order to make it easier to map variables to five-digit Modbus addresses, the Connected 
Components Workbench mapping tool checks the number of characters entered for the 
Modbus Address. If only five-digits are entered, the address is treated as a five-digit Modbus 
address. This means that the Coils are mapped from 00001…09999, Discrete Inputs are 
mapped from 10001…19999, Input Registers are mapped from 30001…39999, and Holding 
Registers are mapping from 40001…49999. 
Example 1, PanelView 800 HMI (Master) to Micro800 (Slave) 
The embedded serial port is targeted for use with HMIs using Modbus RTU. The maximum 
recommended cable distance is 3 meters. Use the 2080-SERIALISOL serial port plug-in module 
if longer distances or more noise immunity is needed.
The HMI is typically configured for Master and the Micro800 embedded serial port is configured 
for Slave. 
From the default Communications Settings for a PanelView 800 HMI (PV800), there are three 
items that must be checked or modified in order to set up communications from PV800 to 
Micro800. 
1. Change from DF1 to Modbus protocol. 
ULINT Y 64 Y 64 Y 4 Y 4
LINT Y64 Y64 Y4 Y4
LREAL Y 64 Y 64 Y 4 Y 4
Table 64 - Mapping Table (Continued)
Variable Data Type
0 - Coils
000001…065536
1 - Discrete Inputs
100001…165536
3 - Input Registers
300001…365536
4 - Holding Registers
400001…465536
Supported
Modbus Address 
Used
Supported
Modbus Address 
Used
Supported
Modbus Address 
Used
Supported
Modbus Address 
Used