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	Data Byte #2	Data Byte #3	Data Byte #4	CRC	CRC
Example 01~FF	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.
Register length	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	unsigned int 16	First byte is 0, due to no definition.
0009	1	error code b	unsigned int 16	First byte is 0, due to no definition.
000A	1	error code c	unsigned int 16	First byte is 0, due to no definition.
000B	1	error code d	unsigned int 16	First byte is 0, due to no definition.
000C	1	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