Chapter 6. Communication; Modbus; Introduction; Modbus Register Map - GE AquaTrans AT600 User Manual

Chapter 6. Communication

6.1 MODBUS

6.1.1 Introduction

The AT600 flow meter generally follows the standard MODBUS communications protocol defined by the
MODBUS APPLICATION PROTOCOL SPECIFICATION V1.1b , which is available at www.modbus.org. With this
reference as a guide, an operator can use any MODBUS master to communicate with the AT600 flow meter.
For the AT600, there are two limits of this implementation:
1. The AT600 supports only four of the standard function codes. These are Read Holding Registers
(0x03), Read Input Registers (0x04), Write Multiple Registers (0x10), and Read File Record (0x14).
2. The AT600 needs a 15 ms gap between Modbus requests. The prime objective of the flow meter is to
measure flow and drive the output, so the Modbus server has a low priority.

6.1.2 MODBUS Register Map

Register Register (in
(in Hex)
100 100
108
118
128
140 140
148
150
158
300 300
304
308
500 500
502
504
506
508
50A
50C
AquaTrans™ AT600 User's Manual
Table 7: MODBUS Register Map
Decimal) Access Level
256 User
264 User
280 User
296 User
320 User
328 User
336 User
344 User
768 RO
772 RO
776 RO
1280 User
1282 User
1284 User
1286 User
1288 User
1290 User
1292 User
Description
Product Short Tag
Product Long Tag
Product message (for HART)
Product descriptor (for HART)
Product Electronic serial
number
Product fixture serial number
Product transducer1 serial
number
Product transducer2 serial
number
Main Hardware version
Option Hardware version
Main Software version
Global Unit group 1 for Actual
Volumetric
Global Unit group 2 for Day
Global Unit group 3 for dB
Global Unit group 4 for Density
Global Unit group 5 for
Dimension
Global Unit group 6 for Hz
Global Unit group 7 for
Viscosity
Chapter 6. Communication
RO/RW Format
RW CHAR * 16
RW CHAR * 32
RW CHAR * 32
RW CHAR * 16
RW CHAR * 16
RW CHAR * 16
RW CHAR * 16
RW CHAR * 16
RO CHAR * 8
RO CHAR * 8
RO CHAR * 8
RW INT32
RW INT32
RW INT32
RW INT32
RW INT32
RW INT32
RW INT32
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