# Read-only memory read instruction(04) and memory lists

## **Instruction example**

Format of command (04) from master

| Byte#          | 1             | 2             | 3                                 | 4                                 | 5                                | 6                                | 7   | 8   |
| -------------- | ------------- | ------------- | --------------------------------- | --------------------------------- | -------------------------------- | -------------------------------- | --- | --- |
| Node ID        | Slave Address | Function Code | Address of first reading register | Address of first reading register | Quantity of registers to be read | Quantity of registers to be read | CRC | CRC |
| Example 01\~FF | 01            | 04            | 00                                | 00                                | 00                               | 02                               | 71  | CB  |

**Description of master command**

The example will read instantaneous flow volume.

slave address: 01(address of this flowmeter)

function code: 04(read instruction)

Address of first reading register: 0000(Address of first register to read)

Quantity of registers to be read: 0002 (need to read 2 registers from 0000)

CRC: 71 CB(Calculating error correcting code according to CRC algorithm)

## **Format of flowmeter response(04)**

| Byte#                       | 1             | 2             | 3                       | 4            | 5                         | 6                         | 7                         | 8   | 9   |
| --------------------------- | ------------- | ------------- | ----------------------- | ------------ | ------------------------- | ------------------------- | ------------------------- | --- | --- |
| Node ID                     | Slave Address | Function Code | Amount of response Byte | Data Byte #1 | <p>Data Byte</p><p>#2</p> | <p>Data Byte</p><p>#3</p> | <p>Data Byte</p><p>#4</p> | CRC | CRC |
| <p>Example</p><p>01\~FF</p> | 01            | 04            | 04                      | 00           | 00                        | 00                        | 00                        | FB  | 84  |

**Description of flowmeter response example**

slave address: 01(address of this flowmeter)

function code: 04(read instruction)

Amount of response Byte: 04 (2 register=4 byte)

Data Byte: 00 00 00 00(Assume the instantaneous flow volume is 0)

CRC: FB 84(Calculating error correcting code according to CRC algorithm)

## **Definition and** address **of memory**

How to use these charts

| Read-write memory type       | Function                                                       |
| ---------------------------- | -------------------------------------------------------------- |
| Register location            | Read-write memory address is not shared with read-only memory. |
| <p>Register</p><p>length</p> | The length of variable memory. The unit is Register(2Byte).    |
| Memory definition            | For memory data description.                                   |
| Data type                    | The format of sending and receiving data type.                 |

**Read-only memory list**

| Register location | Register length | Memory definition                                                                                                                           | Data type       | Remarks                                |
| ----------------- | --------------- | ------------------------------------------------------------------------------------------------------------------------------------------- | --------------- | -------------------------------------- |
| 0000              | 2               | instantaneous flow rate                                                                                                                     | float 32        |                                        |
| 0002              | 2               | instantaneous flow velocity                                                                                                                 | float 32        |                                        |
| 0004              | 2               | totalized flow volume                                                                                                                       | float 32        |                                        |
| 0006              | 2               | analog output in micro-amp                                                                                                                  | unsigned int 32 |                                        |
| 0008              | 1               | [error code a](/qr/fp-as510-paddle-wheel-flowmeter-manual-en-v1/alarm-and-description-of-system-conditions.md#alarm-a-major-abnormality)    | unsigned int 16 | First byte is 0, due to no definition. |
| 0009              | 1               | [error code b](/qr/fp-as510-paddle-wheel-flowmeter-manual-en-v1/alarm-and-description-of-system-conditions.md#alarm-b-out-of-specification) | unsigned int 16 | First byte is 0, due to no definition. |
| 000A              | 1               | [error code c](/qr/fp-as510-paddle-wheel-flowmeter-manual-en-v1/alarm-and-description-of-system-conditions.md#alarm-c-maintenance-required) | unsigned int 16 | First byte is 0, due to no definition. |
| 000B              | 1               | [error code d](/qr/fp-as510-paddle-wheel-flowmeter-manual-en-v1/alarm-and-description-of-system-conditions.md#alarm-d-function-check)       | unsigned int 16 | First byte is 0, due to no definition. |
| 000C              | 1               | [System Status](/qr/fp-as510-paddle-wheel-flowmeter-manual-en-v1/alarm-and-description-of-system-conditions.md#system-status)               | unsigned int 16 | First byte is 0, due to no definition. |
| 000D              | 1               | history\[1] year & month                                                                                                                    | unsigned int 16 |                                        |
| 000E              | 1               | history\[1] day                                                                                                                             | unsigned int 16 |                                        |
| 000F              | 1               | history\[1] total method                                                                                                                    | unsigned int 16 |                                        |
| 0010              | 2               | history\[1] totalized flow volume                                                                                                           | float32         |                                        |
| 0012              | 1               | history\[2] year & month                                                                                                                    | unsigned int 16 |                                        |
| 0013              | 1               | history\[2] day                                                                                                                             | unsigned int 16 |                                        |
| 0014              | 1               | history\[2] total method                                                                                                                    | unsigned int 16 |                                        |
| 0015              | 2               | history\[2] totalized flow volume                                                                                                           | float32         |                                        |
| 0017              | 1               | history\[3] year & month                                                                                                                    | unsigned int 16 |                                        |
| 0018              | 1               | history\[3] day                                                                                                                             | unsigned int 16 |                                        |
| 0019              | 1               | history\[3] total method                                                                                                                    | unsigned int 16 |                                        |
| 001A              | 2               | history\[3] totalized flow volume                                                                                                           | float32         |                                        |
| 001C              | 1               | history\[4] year & month                                                                                                                    | unsigned int 16 |                                        |
| 001D              | 1               | history\[4] day                                                                                                                             | unsigned int 16 |                                        |
| 001E              | 1               | history\[4] total method                                                                                                                    | unsigned int 16 |                                        |
| 001F              | 2               | history\[4] totalized flow volume                                                                                                           | float32         |                                        |
| 0021              | 1               | history\[5] year & month                                                                                                                    | unsigned int 16 |                                        |
| 0022              | 1               | history\[5] day                                                                                                                             | unsigned int 16 |                                        |
| 0023              | 1               | history\[5]total method                                                                                                                     | unsigned int 16 |                                        |
| 0024              | 2               | history\[5] totalized flow volume                                                                                                           | float32         |                                        |
| 0026              | 1               | history\[6] year & month                                                                                                                    | unsigned int 16 |                                        |
| 0027              | 1               | history\[6] day                                                                                                                             | unsigned int 16 |                                        |
| 0028              | 1               | history\[6] total method                                                                                                                    | unsigned int 16 |                                        |
| 0029              | 2               | history\[6] totalized flow volume                                                                                                           | float32         |                                        |
| 002B              | 1               | history\[7] year & month                                                                                                                    | unsigned int 16 |                                        |
| 002C              | 1               | history\[7] day                                                                                                                             | unsigned int 16 |                                        |
| 002D              | 1               | history\[7] total method                                                                                                                    | unsigned int 16 |                                        |
| 002E              | 2               | history\[7] totalized flow volume                                                                                                           | float32         |                                        |
| 0030              | 1               | history\[8] year & month                                                                                                                    | unsigned int 16 |                                        |
| 0031              | 1               | history\[8] day                                                                                                                             | unsigned int 16 |                                        |
| 0032              | 1               | history\[8] total method                                                                                                                    | unsigned int 16 |                                        |
| 0033              | 2               | history\[8] totalized flow rate                                                                                                             | float32         |                                        |
| 0035              | 1               | history\[9] year & month                                                                                                                    | unsigned int 16 |                                        |
| 0036              | 1               | history\[9] day                                                                                                                             | unsigned int 16 |                                        |
| 0037              | 1               | history\[9] total method                                                                                                                    | unsigned int 16 |                                        |
| 0038              | 2               | history\[9] totalized flow rate                                                                                                             | float32         |                                        |
| 003A              | 1               | history\[10] year & month                                                                                                                   | unsigned int 16 |                                        |
| 003B              | 1               | history\[10] day                                                                                                                            | unsigned int 16 |                                        |
| 003C              | 1               | history\[10] total method                                                                                                                   | unsigned int 16 |                                        |
| 003D              | 2               | history\[10] totalized flow rate                                                                                                            | float32         |                                        |
| 003F              | 1               | history\[11] year & month                                                                                                                   | unsigned int 16 |                                        |
| 0040              | 1               | history\[11] day                                                                                                                            | unsigned int 16 |                                        |
| 0041              | 1               | history\[11] total method                                                                                                                   | unsigned int 16 |                                        |
| 0042              | 2               | history\[11] totalized flow rate                                                                                                            | float32         |                                        |
| 0044              | 1               | history\[12] year & month                                                                                                                   | unsigned int 16 |                                        |
| 0045              | 1               | history\[12] day                                                                                                                            | unsigned int 16 |                                        |
| 0046              | 1               | history\[12] total method                                                                                                                   | unsigned int 16 |                                        |
| 0047              | 2               | history\[12] totalized flow rate                                                                                                            | float32         |                                        |
| 0049              | 1               | history\[13] year & month                                                                                                                   | unsigned int 16 |                                        |
| 004A              | 1               | history\[13] day                                                                                                                            | unsigned int 16 |                                        |
| 004B              | 1               | history\[13] total method                                                                                                                   | unsigned int 16 |                                        |
| 004C              | 2               | history\[13] totalized flow rate                                                                                                            | float32         |                                        |
| 004E              | 1               | history\[14] year & month                                                                                                                   | unsigned int 16 |                                        |
| 004F              | 1               | history\[14] day                                                                                                                            | unsigned int 16 |                                        |
| 0050              | 1               | history\[14] total method                                                                                                                   | unsigned int 16 |                                        |
| 0051              | 2               | history\[14] totalized flow rate                                                                                                            | float32         |                                        |

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