Emerson Rosemount 2460 System Hub - Appendix F Modbus Standard Question

187
Modbus
®
Standard Question
Modbus
®
Standard Question
October 2018
Reference Manual
00809-0100-2460, Rev DE
Appendix F Modbus
®
Standard Question
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 187
FC02 Status register area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 188
FC03 register area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 190
FC04 register area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 191
User defined Modbus mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 199
F.1 Introduction
The Rosemount
™
2460 System Hub polls field devices and stores the information in input registers. This
allows Rosemount TankMaster and other host systems to read measurement data and status information
for a large number of tanks. This appendix lists the input registers which can be scanned in queries from
a Modbus master.
F.1 .1 Pr io ri t y
Polling will occur at certain intervals as specified in the table below:
Table F-1. Read interval
Priority Register Area Read interval in master
1
 Level
1 per second
2
 Average Temperature
 Pressure
1 per 10 seconds
3
 Temperature Element
 Density
1 per 30 seconds
4
 Free Water Level
 Ambient Air Temperature
 Ambient Air Pressure
 Relay State
1 per 60 seconds
5
 Units
 Diagnostic
1 per 120 seconds