GE AT600 User Manual

AT600 User’s Manual 77
Chapter 5. Communication
Chapter 5. Communication
5.1 MODBUS
5.1.1 Introduction
In general, the AT600 flowmeter follows the standard MODBUS communications protocol defined by the reference
MODBUS APPLICATION PROTOCOL SPECIFICATION V1.1b. This specification is available at www.modbus.org
on the Internet. With this reference as a guide, an operator could use any MODBUS master to communicate with the
flowmeter.
Listed below 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 flowmeter needs a 15 ms gap between Modbus requests. The prime objective of the flowmeter is to measure
flow and drive the output, so the Modbus server has a low priority.
5.1.2 MODBUS Map
Table 5: MODBUS Map
Register
(in Hex)
Register (in
Decimal) Access Level Description RO/RW Format
100 100 256 User Product Short Tag RW CHAR * 16
108 264 User Product Long Tag RW CHAR * 32
118 280 User Product message (for HART) RW CHAR * 32
128 296 User Product descriptor (for HART) RW CHAR * 16
140 140 320 User
Product Electronic serial
number RW CHAR * 16
148 328 User Product fixture serial number RW CHAR * 16
150 336 User
Product transducer1 serial
number RW CHAR * 16
158 344 User
Product transducer2 serial
number RW CHAR * 16
300 300 768 RO Main Hardware version RO CHAR * 8
304 772 RO Option Hardware version RO CHAR * 8
308 776 RO Main Software version RO CHAR * 8
500 500 1280 User
Global Unit group 1 for
Actual Volumetric RW INT32
502 1282 User Global Unit group 2 for Day RW INT32
504 1284 User Global Unit group 3 for dB RW INT32
506 1286 User
Global Unit group 4 for
Density RW INT32

GE AT600 Specifications

General

Brand	GE
Model	AT600
Category	Measuring Instruments
Language	English