C
Y
K
Tech
www.ceyeko.com
Page 20
C h a p t e r 5
: C o m m u n i c a t i o n
The instrument is provided with standard RS485 series communication interface, in
accordance with international universal standard MODBUS-RTU communication protocol,
supporting No.03 register reading and holding command. MODBUS standard format (No.03
register reading and holding command)
Command Format:
Definition
Address
Function
Code
Register
Address
Number of
Data
CRC Check
Data
ADDR
0x03
M
N
CRC 16
Number of Bytes
1
1
2
2
2
Return Format:
Definition
Address
Function
Code
Register
Address
Number of
Data
CRC Check
Data
ADDR
0x03
2*N
Data
CRC 16
Number of Bytes
1
1
1
2*N
2
Register Address Description :
Address
Data Type
Data Size
Function
Code
Description
Access
Authority
0x0000
Unsigned
Long
4 Bytes
0x03
pH Value (default two
decimal places)
Read Only
0x0002
Short
2 Bytes
0x03
Temperature
(default 1 decimal)
Read Only
0x0003
Unsigned
Long
4 Bytes
0x03
ORP Value
(signed integer)
Read Only
