7. MODBUS Communication Protocol
Read instantaneous flow rate, flow speed, RSSI, and signal quality:
0
1
2
3
4
5
6
7
Node ID
Funtion Code
Address 1
Address 0
Data 1
Data 0
CRC
CRC
01~FF
04
00
00
00
07
16 Bit CRC Calculation results
16 Bit CRC Calculation results
Response format:
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Node ID
Funtion Code
Data length
Integer part of flow rate
Integer part of flow rate
Fraction part of flow rate
Fraction part of flow rate
Integer part of flow speed
Integer part of flow speed
Fraction part of flow speed
Fraction part of flow speed
Upstream RSSI
Downstream RSSI
Reserved
Signal quality
Unit
Metric/Imperial
CRC
CRC
01~FF
04
0D
0
16 Bit CRC Calculation results
16 Bit CRC Calculation results
Byte 00 : Node ID
Byte 01 : Function code
Byte 02 : Data length 10 bytes
Byte 03 ~ 04 : Integer part of totalized positive flow rate, Format: 16-bit signed integer
Byte 05 ~ 06 : Fraction part of totalized positive flow rate, Format: 16-bit signed integer, divide by 10000 before add to integer part
Byte 07 ~ 08 : Integer part of totalized positive flow speed, Format: 16-bit signed integer
Byte 09 ~ 10 : Fraction part of totalized positive flow speed, Format: 16-bit signed integer, divide by 10000 before add to integer part
Byte 11, 12 : 8-bit unsigned integer, value is between 0 and 100
Byte 14 : 8-bit unsigned integer, value is between 0 and 100
Byte 15 : 8-bit unsigned integer, convert this number from hexadecimal to decimal, the digit in tens represents the unit of numerator and the digit in ones represents the unit of denominator. The table below shows the corresponding unit for each number.
Byte 16 : 8-bit unsigned integer,value is 1 or 2. 1 stands for Metric, 2 stands for Imperial.
Numerator :
Number
Unit
1
Cubic meter (m³)
2
Liter (l)
3
USA gallon (gal)
4
Imperial Gallon (igl)
5
Million USA gallon (Mgl)
6
Cubic feet (cf)
7
USA liquid barrel (bal)
8
Oil barrel (ob)
Denominat :
Number
Unit
1
Second
2
Minute
3
Hour
4
Day
Read totalized positive (forward-direction) flow rate :
0
1
2
3
4
5
6
7
Node ID
Funtion Code
Address 1
Address 0
Data 1
Data 0
CRC
CRC
01~FF
04
00
07
00
05
16 Bit CRC Calculation results
16 Bit CRC Calculation results
Response format:
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Node ID
Funtion Code
Data length
Integer part of totalized positive flow rate
Integer part of totalized positive flow rate
Integer part of totalized positive flow rate
Integer part of totalized positive flow rate
Fraction part of totalized positive flow rate
Fraction part of totalized positive flow rate
Fraction part of totalized positive flow rate
Fraction part of totalized positive flow rate
Reserved
Unit
CRC
CRC
01~FF
04
0A
0
16 Bit CRC Calculation results
16 Bit CRC Calculation results
Byte 00 : Node ID
Byte 01 : Function code
Byte 02 : Data length 10 bytes
Byte 03 ~ 06 : 32-bits signed integer
Byte 07 ~ 10 : 32-bits signed integer, divide by 1000000 before add to integer part
Byte 12 : Value is between 1 and 8. The table below shows the corresponding unit for each number.
Number
Unit
1
Cubic meter (m³)
2
Liter (l)
3
USA gallon (gal)
4
Imperial Gallon (igl)
5
Million USA gallon (Mgl)
6
Cubic feet (cf)
7
USA liquid barrel (bal)
8
Oil barrel (ob)
Read totalized negative (reverse-direciton) flow rate:
0
1
2
3
4
5
6
7
Node ID
Funtion Code
Address 1
Address 0
Data 1
Data 0
CRC
CRC
01~FF
04
00
0C
00
05
16 Bit CRC Calculation results
16 Bit CRC Calculation results
Response format:
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Node ID
Funtion Code
Data length
Integer part of totalized negative flow rate
Integer part of totalized negative flow rate
Integer part of totalized negative flow rate
Integer part of totalized negative flow rate
Fraction part of totalized negative flow rate
Fraction part of totalized negative flow rate
Fraction part of totalized negative flow rate
Fraction part of totalized negative flow rate
Reserved
Unit
CRC
CRC
01~FF
04
0A
0
16 Bit CRC Calculation results
16 Bit CRC Calculation results
Byte 00 : Node ID
Byte 01 : Function code
Byte 02 : Data length 10 bytes
Byte 03 ~ 06 : 32-bits signed integer
Byte 07 ~ 10 : 32-bits signed integer, divide by 1000000 before add to integer part
Byte 12 : Value is between 1 and 8. The table below shows the corresponding unit for each number.
Number
Unit
1
Cubic meter (m³)
2
Liter (l)
3
USA gallon (gal)
4
Imperial Gallon (igl)
5
Million USA gallon (Mgl)
6
Cubic feet (cf)
7
USA liquid barrel (bal)
8
Oil barrel (ob)
Read totalized net flow rate:
0
1
2
3
4
5
6
7
Node ID
Funtion Code
Address 1
Address 0
Data 1
Data 0
CRC
CRC
01~FF
04
00
11
00
05
16 Bit CRC Calculation results
16 Bit CRC Calculation results
Response format:
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Node ID
Funtion Code
Data length
Integer part of totalized net flow rate
Integer part of totalized net flow rate
Integer part of totalized net flow rate
Integer part of totalized net flow rate
Fraction part of totalized net flow rate
Fraction part of totalized net flow rate
Fraction part of totalized net flow rate
Fraction part of totalized net flow rate
Reserved
Unit
CRC
CRC
01~FF
04
0A
0
16 Bit CRC Calculation results
16 Bit CRC Calculation results
Byte 00 : Node ID
Byte 01 : Function code
Byte 02 : Data length 10 bytes
Byte 03 ~ 06 : 32-bits signed integer
Byte 07 ~ 10 : 32-bits signed integer, divide by 1000000 before add to integer part
Byte 12 : Value is between 1 and 8. The table below shows the corresponding unit for each number.
Number
Unit
1
Cubic meter (m³)
2
Liter (l)
3
USA gallon (gal)
4
Imperial Gallon (igl)
5
Million USA gallon (Mgl)
6
Cubic feet (cf)
7
USA liquid barrel (bal)
8
Oil barrel (ob)
Clear all totalized flow rate:
0
1
2
3
4
5
6
7
Node ID
Funtion Code
Address 1
Address 0
Data 1
Data 0
CRC
CRC
01~FF
14
00
00
00
00
16 Bit CRC Calculation results
16 Bit CRC Calculation results
Clear totalized net flow rate:
0
1
2
3
4
5
6
7
Node ID
Funtion Code
Address 1
Address 0
Data 1
Data 0
CRC
CRC
01~FF
15
00
00
00
00
16 Bit CRC Calculation results
16 Bit CRC Calculation results
Clear totalized positive (forward-direction) flow rate:
0
1
2
3
4
5
6
7
Node ID
Funtion Code
Address 1
Address 0
Data 1
Data 0
CRC
CRC
01~FF
16
00
00
00
00
16 Bit CRC Calculation results
16 Bit CRC Calculation results
Clear totalized negative (reverse-direction) flow rate:
0
1
2
3
4
5
6
7
Node ID
Funtion Code
Address 1
Address 0
Data 1
Data 0
CRC
CRC
01~FF
17
00
00
00
00
16 Bit CRC Calculation results
16 Bit CRC Calculation results
Last updated