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 | Content | Content | Content | Content | Content | Content | Content | Content | Content | Content | 0 | Content | Content | Content | 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 | 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 |
Response format:
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 |
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 | 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 |
Response format:
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 |
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 | 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 |
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 | 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 |
Clear totalized net flow rate:
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 |
Clear totalized positive (forward-direction) flow rate:
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 |
Clear totalized negative (reverse-direction) flow rate:
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 |
7.6 Read upstream and downstream PT1000 temperature, instantaneous flow and error bits: (available starting from fw 1.2.2)
Read upstream and downstream PT1000 temperature, instantaneous flow and error bits:
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 |
Response format:
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 |
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
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