7. MODBUS Communication Protocol
Last updated
Last updated
Read instantaneous flow rate, flow speed, RSSI, and signal quality:
Response format:
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 :
Denominat :
Read totalized positive (forward-direction) flow rate :
Response format:
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.
Read totalized negative (reverse-direciton) flow rate:
Response format:
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.
Read totalized net flow rate:
Response format:
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.
Clear all totalized flow rate:
Clear totalized net flow rate:
Clear totalized positive (forward-direction) flow rate:
Clear totalized negative (reverse-direction) flow rate:
Read upstream and downstream PT1000 temperature, instantaneous flow and error bits:
Response format:
Byte 00 : Node ID
Byte 01 : Function code
Byte 02 : Data length 8 bytes
Byte 03 ~ 04 : Upstream temperature multiplied by 10, rounded to the nearest integer (format: 16-Bit signed integer multiplied by ten)
Byte 05 ~ 06 : Downstream temperature multiplied by 10, rounded to the nearest integer (Format: 16-Bit signed integer multiplied by ten)
Byte 07 ~ 08 : Integer part of the flow rate, format: 16-Bit signed integer
Byte 09 ~ 10 : Decimal portion of the flow rate , format: 16-Bit signed integer, before adding it to the integer portion, divide it by 10000
Byte 12 : error code
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
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
Content
Content
Content
Content
Content
Content
Content
Content
Content
Content
0
Content
Content
Content
16 Bit CRC Calculation results
16 Bit CRC Calculation results
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)
Number
Unit
1
Second
2
Minute
3
Hour
4
Day
0
1
2
3
4
5
6
7
Node ID
Function 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
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Node ID
Function 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
Content
Content
Content
Content
Content
Content
Content
Content
0
Content
16 Bit CRC Calculation results
16 Bit CRC Calculation results
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)
0
1
2
3
4
5
6
7
Node ID
Function 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
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Node ID
Function 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
Content
Content
Content
Content
Content
Content
Content
Content
0
Content
16 Bit CRC Calculation results
16 Bit CRC Calculation results
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)
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
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Node ID
Function 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
Content
Content
Content
Content
Content
Content
Content
Content
0
Content
16 Bit CRC Calculation results
16 Bit CRC Calculation results
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)
0
1
2
3
4
5
6
7
Node ID
Function 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
0
1
2
3
4
5
6
7
Node ID
Function 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
0
1
2
3
4
5
6
7
Node ID
Function 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
0
1
2
3
4
5
6
7
Node ID
Function 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
0
1
2
3
4
5
6
7
Node ID
Function Code
Address 1
Address 0
Data 1
Data 0
CRC
CRC
01~FF
04
00
16
00
05
16 Bit CRC Calculation results
16 Bit CRC Calculation results
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Node ID
Function Code
Data length
Upstream temperature multiplied by 10, rounded to the nearest integer (format: 16-Bit signed integer multiplied by ten)
Upstream temperature multiplied by 10, rounded to the nearest integer (format: 16-Bit signed integer multiplied by ten)
Downstream temperature multiplied by 10, rounded to the nearest integer (Format: 16-Bit signed integer multiplied by ten)
Downstream temperature multiplied by 10, rounded to the nearest integer (Format: 16-Bit signed integer multiplied by ten)
Integer portion of the flow rate (format: 16-Bit signed integer)
Integer portion of the flow rate (format: 16-Bit signed integer)
Decimal portion of the flow rate (format: 16-Bit signed integer). It needs to be divided by 10000 before being added to the integer portion.
Decimal portion of the flow rate (format: 16-Bit signed integer). It needs to be divided by 10000 before being added to the integer portion.
Reserved
error code
CRC
CRC
01~FF
04
0A
00
00
00
00
00
00
00
00
00000000
16 Bit CRC Calculation results
16 Bit CRC Calculation results