SMC Networks HECR Series Communications Manual

MODBUS communication function
HECR 5-8
5.8 Explanation of function codes
5.8.1 Function code：03H Reading multiple registers
Register data of assigned points from assigned address is read.
◼ Request message <Normal> (Master to Slave)
Start
Slave Address
Function
Data
LRC
End
[:]
XX
XX
[0]
[3]
XX
XX
[CR]
[LF]
Read Address
Quantity to Read
Hi
Lo
Hi
Lo
XX
XX
XX
XX
XX
XX
XX
XX
◼ Response message<Normal> (Slave to Master)
Start
Slave Address
Function
Data
LRC
End
[:]
XX
XX
[0]
[3]
XX
XX
[CR]
[LF]
Byte Count
Read Data1
Read Data n
Hi
Lo
Hi
Lo
XX
XX
XX
XX
XX
XX
XX
XX
XX
XX
◼ Communication example
1) Slave Address (=Unit number): No.1
2) Read three consecutive data from register 0040H.
(Read internal sensor temperature, external sensor temperature, average temperature.)
Request message
Response message
Code
Contents
Code
Contents
01
Slave Address
01
Slave Address
03
Function
03
Function
0040
Head address of specified register
06
Quantity of bytes to read
0003
Quantity of register to read
09E1
Information of 0040H
(internal sensor temperature)
B9
LRC
FC22
Information of 0041H
(external sensor temperature)
FC22
Information of 0042H
(average temperature=external temperature)
D0
LRC
This product
(Request):010300400003B9 [CR][LF]
(Response):01030609E1FC22FC22D0 [CR][LF]
Your system
Data is sent and
received in ASCII
code.

SMC Networks HECR Series Specifications

General

Brand	SMC Networks
Model	HECR Series
Category	Chiller
Language	English