Model 3095FB Multivariable Transmitter with Modbus Protocol
Modbus Protocol Guide
Page 4 of 79
1.0 Introduction
The readers of this document are expected to have a general understanding of the Modbus proto-
col. If you do not have the required knowledge of the Modbus protocol, the Modbus documents
referenced in Section 1.2, on page 4 of this document should be of help. Also Section 2.0, on
page 6 of this document contains a brief overview of the Modbus protocol.
1.1 Purpose
The purpose of this document is to provide the information required to implement within a
host, an effective exchange of data with the Rosemount 3095FB Multivariable Transmitter
with Modbus Protocol. This document defines the Modbus interface and register layout in suf-
ficient detail for the 3095FB.
1.2 References
Modicon Modbus Protocol Reference Guide
1.3 Abbreviations, Definitions, and Acronyms
Table 1-1 Glossary
Term
Description
AP
absolute pressure - above absolute zero pressure
C
degrees Celsius (5 / 9) * (T(F) - 32)
coil
A read/write bit register
Conventional Symbol
A symbol which is commonly used in the gas industry in equa-
tions or algorithms or other expressions
CRC
Cyclic Redundancy Check
default value
The initial value set by software. Some of these may be overwrit-
ten by the user via Modbus commands.
discrete input
A read only bit register
DP
differential pressure
F
degrees Fahrenheit (9 / 5) * T(C) + 32
FP
IEEE-754 floating point
floating point register
Two consecutive 16 bit registers that store an IEEE 754 floating
point number
