Modbus protokoll rs485

Modbus Funktions Codes

Hex Data					Funktion
adr	fc	data .....
..	01	..	..	..	Lese Ausgangsbit Status
..	02	..	..	..	Lese Eingangsbit Status
..	03	..	..	..	Lese Holding-Register Analog Ausgang
..	04	..	..	..	Lese Input-Register Analog Eingang
..	05	..	..	..	Schreibe Ausgangsbit
..	06	..	..	..	Schreibe Holding-Register Analog Ausgang
..	0F	..	..	..	* Funktion noch offen
..	10	..	..	..	wird bei den China Modulen zum Anpassen der UID benutzt
..	15	..	..	..	Schreibe mehrfach Ausgangsbit
..	16	..	..	..	Schreibe mehrfach Holding-Register (Daten für >16-bit) Analog Ausgang
..	23	..	..	..	* Funktion noch offen

• das sind wohl noch nicht alle Modbus Funktion Codes

es gibt wohl auch Sonderfunktionen die nur bei bstimmten Geräten vorhanden sind hier z.B. 0x10h setzten der UID

adr -> device Adress oder auch UID - 1 Byte lang
fc -> Function Code 1 Byte
data -> n Bytes

Modbus RTU Instructions:

Baud rate: 9600 8 NONE 1

Hexadecimal send
hexadecimal receive

Operation steps:
1. Software settings communication baud rate
2. Set the address (communication using the device address, the default address is 01)

Set the address from from Broadcast to 0x01 , 0x02 , 0x03

Hex Byte	Funktion
00 10 00 00 00 01 02 00 01 6A 00	Broadcast Address Modified to 01
00 10 00 00 00 01 02 00 02 2A 01	Broadcast Address Modified to 02
00 10 00 00 00 01 02 00 03 EB C1	Broadcast Address Modified to 03

Read Address at Broadcast Call

Hex Byte	Funktion
00 03 00 00 00 01 85 db	Send to Device ( Broadcast )
00 03 02 00 01 44 44	Receive from Device 01 for Address
00 03 02 00 02 04 45	Receive from Device 02 for Address
00 03 02 00 03 C5 85	Receive from Device 03 for Address

Modbus Rtu 2

Hardware Resources: Data register address

 *   RS485 communication interface
 *   TTL communication interface
 *   2 Input ( max. DC +12 Volt UB ) 
 *   2 Relay Output 
 *   A user button
 *   A user LED
 *   A power indicator
 *   A STM32F030F4 microcontroller
 *   2 relay status indicators LED lights
 *   Power supply terminal interface (12V power supply)

Meaning of each byte:

Byte 1: address
byte 2: function
byte 3 4: register address
byte 5 6: register data
byte 7 8: CRC check

[address 1 bzw. UID 0x01]

Switch Single

Hex Data								Funktion
Adresse	Funktion	Reghigh	Reglow	Data 1	Data 2	CRChigh	CRClow	Funktion
01	05	00	00	FF	00	8C	3A	0 relay ON
01	05	00	00	00	00	CD	CA	0 relay off
01	05	00	01	FF	00	DD	FA	1 relay ON
01	05	00	01	00	00	9C	0A	1 relay off

all Funktion

Hex Data								Funktion
Adresse	Funktion	Reghigh	Reglow	Data 1	Data 2	Data 3	Data 4	CRChigh	CRClow	Funktion
01	0F	00	00	00	08	01	00	FE	95	Full Relay off
01	0F	00	00	00	08	01	FF	BE	D5	Full Relay on
01	02	00	00	00	08			79	CC	Send : Read all input switch status
01	02	01	00					A1	88	Return : 8 input states

Quelle - https://hacktronics.co.in/2-channel-relay-module/modbus-rtu-2-way-relay-output-2-way-input-switch-ttl-rs485-interface-communication

Modbus Rtu 4

Specifications:

 *   RS485 communication interface
 *   TTL communication interface
 *   4 Input ( Switch to GND !!!! NO + UB !!! )
 *   4 Relay Output 
 *   2 user button
 *   A user LED
 *   A power indicator
 *   A STM32F030F4 microcontroller
 *   4 relay status indicators LED lights
 *   Power supply terminal interface (12V power supply)

[address 1]

Hex Byte	Funktion
01 05 00 01 01 00 9d 9a	No. 1 relay ON
01 05 00 01 00 00 9c 0a	No. 1 relay off
01 05 00 02 01 00 6d 9a	No. 2 relay ON
01 05 00 02 00 00 6c 0a	No. 2 relay off
01 05 00 03 01 00 3c 5a	No. 3 relay ON
01 05 00 03 00 00 3d ca	No. 3 relay off
01 05 00 04 01 00 8d 9b	No. 4 relay ON
01 05 00 04 00 00 8c 0b	No. 4 relay off
01 05 00 ff 00 00 fd fa	Quanmie
01 05 00 ff ff ff fc 4a	All light

[address 2]

Hex Byte	Funktion
02 05 00 01 01 00 9d a9	No. 1 relay ON
02 05 00 01 00 00 9c 39	No. 1 relay off
02 05 00 02 01 00 6d a9	No. 2 relay ON
02 05 00 02 00 00 6c 39	No. 2 relay off
02 05 00 03 01 00 3c 69	No. 3 relay ON
02 05 00 03 00 00 3d f9	No. 3 relay off
02 05 00 04 01 00 8d a8	No. 4 relay ON
02 05 00 04 00 00 8c 38	No. 4 relay off
02 05 00 ff 00 00 fd c9	Quanmie
02 05 00 ff ff ff fc 79	All light

[address 1]

Small text</small

Hex Byte	Funktion
01 01 00 01 00 04 6c 09	Send : No. 1 relay 1 channel status
	Return ......
01 01 00 02 00 04 9c 09	Send : No. 1 Relay 2 channel status
	Return ......
01 01 00 03 00 04 CD C9	Send : No. 1 Relay 3 channel status
	Return ......
01 01 00 04 00 04 7C 08	Send : No. 1 Relay 4 channel status

hacktronics.co.in/4-channel-relay-module
github Board-C0135

Modbus_RTU_4_Way_Relay_Module.pdf

DDS578R Energy Meter

MODBUS-RTU communication protocol Description:

1.the data format:
Address + function code + data + CRC check code

2.the register type
This meter uses two types of registers, individually addressed
The first is the data register, read-only, using the command code 0x04 to read.
The second category is the parameter register, readable and writable, using the command code 0x03
read, write parameters using 0x10

3.the data format
Float type data: Read the internal data within the meter in line with IEEE-754 standardv floating-point number, data format is 32-bit 4-byte single-precision floating-point data format.

4、Data register list

Data register address				Register Description
adr	fc	highByte	lowByte	Description	unit	Format	Mode
xx	03	00	00	A phase voltage	V	Floating point	Read-only
xx	03	00	02	B phase voltage	V	Floating point	Read-only
xx	03	00	04	C phase voltage	V	Floating point	Read-only
xx	03	00	08	A line current	A	Floating point	Read-only
xx	03	00	0A	B line current	A	Floating point	Read-only
xx	03	00	0C	C line current	A	Floating point	Read-only
xx	03	00	10	Total active power	KWh	Floating point	Read-only
xx	03	00	12	A phase active power	KWh	Floating point	Read-only
xx	03	00	14	B phase active power	KWh	Floating point	Read-only
xx	03	00	16	C phase active power	KWh	Floating point	Read-only
xx	03	00	18	Total reactive power	KWh	Floating point	Read-only
xx	03	00	1A	A phase reactive power	Var	Floating point	Read-only
xx	03	00	1C	B phase areactive power	Var	Floating point	Read-only
xx	03	00	1E	C phase reactive power	Var	Floating point	Read-only
xx	03	00	2A	A phase power factor		Floating point	Read-only
xx	03	00	2E	B phase power factor		Floating point	Read-only
xx	03	00	2C	C phase power factor		Floating point	Read-only
xx	03	00	36	frequency	frequency	Floating point	Read-only
xx	03	01	00	Total active electricity power	KWh	Floating point	Read-only
xx	03	04	00	Total reactive electricity power	KWh	Floating point	Read-only

The second category register (parameter register) read and operate read the meter Address:

(HEX):01 03 00 08 00 02 45 C9

Date descriptions

Data	Detailed description
0x01	Instrument address ( adr )
0x03	Function code, read parameter register ( fc )
0x00 0x08	reading the data from the 00 08 meter internal register address
0x00 0x02	Read data length for two words( four bytes )of data
0x45 0xC9	CRC checksum data for the front, where the high front and low in the post

Returns Data (HEX) 01 04 03 40 00 00 00 EF F3

Data	Detailed description
0x01	Instrument address
0x03	Function code, read parameter register
0x04	Returned data length is 4 bytes of data length
0x40 0x00 0x00 0x00	TUSB To RS485 Converterhe data returned as a 4-byte data type float
0xEF 0xF3	CRC checksum data for the front, where the high front and low in the post

USB To RS485 Converter

USB-To-RS485-Converter

ll /sys/class/tty/*/device/driver
lrwxrwxrwx 1 root root 0 Dez 21 19:30 /sys/class/tty/ttyUSB0/device/driver -> ../../../../../../../../bus/usb-serial/drivers/pl2303/

lsusb
Bus 003 Device 014: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port

https://developer.toradex.com/knowledge-base/uart-(linux)