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

The length of total register requested by a single reading command must be less than or equal to 20 registers. Instructions longer than this will be ignored.

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

Function	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	instantaneous flow rate	int 32	The value is the cumulative flow X100 integer
0008	2	instantaneous flow velocity	int 32	The value is the cumulative flow X100 integer
000A	2	totalized flow volume	int 32	The value is the cumulative flow X100 integer
000C	2	Iout current value uA	unsigned int 32
000E	1	error code a	unsigned int 16	First byte is 0, due to no definition.
000F	1	error code b	unsigned int 16	First byte is 0, due to no definition.
0010	1	error code c	unsigned int 16	First byte is 0, due to no definition.
0011	1	error code d	unsigned int 16	First byte is 0, due to no definition.
0012	1	System Status	unsigned int 16	First byte is 0, due to no definition.