Difference between revisions of "Modbus protokoll rs485"

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(Modbus Rtu 4)
(Modbus Rtu 4)
 
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Line 1: Line 1:
 +
=== Modbus Funktions Codes ===
 +
 +
{| class="wikitable"
 +
! colspan="5"| Hex Data !! colspan="1"| Funktion
 +
|-
 +
| adr || fc  || ! colspan="3"| 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  || ..  ||  ..  ||..  || * Funktion noch offen
 +
|-
 +
| ..  || 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 Code
 +
<br>
 +
adr  -> device Adress 1 Byte <br>
 +
fc  -> Function Code 1 Byte <br>
 +
data -> n Bytes<br> 
 +
 +
* das sind wohl noch nicht alle Modbus Funktion Code
 +
 
=== Modbus Rtu 2 ===
 
=== Modbus Rtu 2 ===
  
 
Hardware Resources:
 
Hardware Resources:
 
+
Data register address
 
   *  RS485 communication interface
 
   *  RS485 communication interface
 
   *  TTL communication interface
 
   *  TTL communication interface
Line 27: Line 66:
 
<br>
 
<br>
 
Set the address from 01 to 09 or from Broadcast to 09
 
Set the address from 01 to 09 or from Broadcast to 09
 +
  
 
{| class="wikitable"
 
{| class="wikitable"
Line 62: Line 102:
  
 
[address 1]<br>
 
[address 1]<br>
 +
 +
Switch Single
  
 
{| class="wikitable"
 
{| class="wikitable"
 +
! colspan="8"| Hex Data !! colspan="1"| Funktion
 
|-
 
|-
! Hex Byte !! 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   ||    FF   ||  00     ||    8C ||  3A || 0 relay ON
 
|-
 
|-
| 01 05 00 00 00 00 CD CA   || 0 relay off
+
| 01       || 05       ||  00   ||    00   ||    00   ||  00     ||    CD ||  CA || 0 relay off  
 
|-
 
|-
|    ||  
+
| 01      || 05        ||  00  ||    01  ||    FF  ||  00    ||    DD  ||  FA  || No. 1 relay ON
 
|-
 
|-
| 01 05 00 01 FF 00 DD FA || No. 1 relay ON
+
| 01       || 05       ||  00   ||    01   ||    00   ||  00    ||    9C  ||  0A  || No. 1 relay off
 
|-
 
|-
| 01 05 00 01 00 00 9C 0A || No. 1 relay off
+
| 01       || 05       ||  00   ||    02  ||    FF  ||  00     ||    2D  ||  FA  || No. 2 relay ON
 
|-
 
|-
|    ||  
+
| 01      || 05        ||  00  ||    02  ||    00  ||  00    ||    6C  ||  0A  || No. 2 relay off
 
|-
 
|-
| 01 05 00 02 FF 00 2D FA || No. 2 relay ON
+
|}
 +
 
 +
 
 +
Switch all
 +
 
 +
{| class="wikitable"
 +
! colspan="8"| Hex Data !! colspan="1"| Funktion
 
|-
 
|-
| 01 05 00 02 00 00 6C 0A || No. 2 relay off
+
| 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 off
 
|-
 
|-
| 01 0F 00 00 00 08 01 00 FE 95 || Full off
+
| 01       || 0F       ||  00   ||    00   ||    00 ||  08   ||    01 ||  FF  ||  BE    || D5    || Full on
 
|-
 
|-
| 01 0F 00 00 00 08 01 FF BE D5 || all bright
+
|         ||          ||        ||        ||        ||        ||        ||        ||        ||        ||  
 
|-
 
|-
|    ||  
+
| 01      || 01        ||  00  ||    00  ||    00  ||  08  ||        ||        ||  BE    || D5    || Send : Read all relay states
 
|-
 
|-
| 01 01 00 00 00 08 3D CC || Send : Read all relay states
+
| 01       || 01        ||  01   ||    00   ||        ||        ||        ||        ||  51    || 88    || Return : Relay fully closed
 
|-
 
|-
| 01 01 01 00 51 88 || Return : Relay fully closed
+
| 01       || 01       ||  01   ||    03  ||        ||        ||        ||        || 11    || 89    || Return : All relays are on
 
|-
 
|-
| 01 01 01 03 11 89  || Return : All relays are on
+
|         ||          ||        ||        ||        ||        ||        ||        ||        ||        ||  
 
|-
 
|-
|    ||  
+
| 01      || 02        ||  00   ||   00    ||  00    ||  08    ||        ||        ||  79    || CC    || Send : Read all input switch status
 
|-
 
|-
| 01 02 00 00 00 08 79 CC  || Send : Read all input switch status
+
| 01     || 02       ||  01    ||  00   ||        ||        ||        ||       || A1     || 88     || Return : 8 input states  
|-
 
| 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 ===
 
=== Modbus Rtu 4 ===
Line 146: Line 195:
  
  
 +
[address 1]<br>
 +
 +
{| class="wikitable"
 +
|-
 +
! 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]<br>
 +
 +
{| class="wikitable"
 +
|-
 +
! Hex Byte  !! Funktion 
 +
|-
 +
| 02 05 00 01 01 00 9d a9 || No. 1 relay ON
 +
|-No. 1 relay 1 channel status
 +
| 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
 +
|}
 +
<br>
 +
[address 1]<br>
 +
{| class="wikitable"
 +
|-<gallery>
 +
<small>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
 +
|}
 +
 +
<br>
 +
 +
 +
 +
[https://hacktronics.co.in/4-channel-relay-module/4-channel-relay-module-programmable-w-opto-isolated-rs485-stm8s103f3 hacktronics.co.in/4-channel-relay-module]
 +
<br>
 +
[https://github.com/TG9541/stm8ef/wiki/Board-C0135 github Board-C0135]
 +
 +
[https://wiki.chaosdorf.de/images/1/14/Modbus_RTU_4_Way_Relay_Module.pdf Modbus_RTU_4_Way_Relay_Module.pdf]
 +
 +
===  DDS578R Energy Meter ===
 +
 +
MODBUS-RTU communication protocol Description:
 +
 +
1.the data format: <br>
 +
Address + function code + data + CRC check code<br>
 +
<br>
 +
2.the register type<br>
 +
This meter uses two types of registers, individually addressed<br>
 +
The first is the data register, read-only, using the command code 0x04 to read.<br>
 +
The second category is the parameter register, readable and writable, using the command code 0x03<br>
 +
read, write parameters using 0x10<br>
 +
<br>
 +
3.the data format<br>
 +
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.<br>
 +
<br>
 +
4、Data register list<br>
 +
 +
{| class="wikitable"
 +
! colspan="4"| Data register address !! colspan="6"| 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:<br>
 +
 +
(HEX):01 03 00 08 00 02 45 C9<br>
 +
 +
Date descriptions
 +
 +
{| class="wikitable"
 +
|-
 +
! 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
 +
 +
{| class="wikitable"
 +
|-
 +
! 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
 +
|-
 +
|}
 
<br>
 
<br>
https://hacktronics.co.in/4-channel-relay-module/4-channel-relay-module-programmable-w-opto-isolated-rs485-stm8s103f3
+
<br>
 +
<br>
 +
 
 +
===  USB To RS485 Converter ===
 +
<br>
 +
[https://www.ebay.de/itm/USB-To-RS485-Converter-Industrial-Upgrade-Protection-RS-485-USB-2-0-Converter/401720933781 USB-To-RS485-Converter] 
 +
<br>
 +
<br>
 +
''ll /sys/class/tty/*/device/driver''<br>
 +
lrwxrwxrwx 1 root root 0 Dez 21 19:30 /sys/class/tty/ttyUSB0/device/driver -> ../../../../../../../../bus/usb-serial/drivers/pl2303/<br>
 +
<br>
 +
''lsusb''<br>
 +
Bus 003 Device 014: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port<br>
 +
<br>
 +
<br>
 +
 
 +
https://developer.toradex.com/knowledge-base/uart-(linux)

Latest revision as of 20:39, 22 December 2019

Modbus Funktions Codes[edit]

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 .. .. .. * Funktion noch offen
.. 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 Code


adr -> device Adress 1 Byte
fc -> Function Code 1 Byte
data -> n Bytes

  • das sind wohl noch nicht alle Modbus Funktion Code

Modbus Rtu 2[edit]

Hardware Resources: Data register address

 *   RS485 communication interface
 *   TTL communication interface
 *   2 optocoupler isolation input
 *   2 way optocoupler isolation 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)


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 01 to 09 or from Broadcast to 09


Hex Byte Funktion
01 10 00 00 00 01 02 00 09 66 56 Current address 01 is changed to 09
00 10 00 00 00 01 02 00 09 6B C6 Broadcast Address Modified to 09



Read Address

Hex Byte Funktion
00 03 00 00 00 01 85 db Send to Device
00 03 02 00 01 44 44 Receive from Device 01 for Address

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]

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 No. 1 relay ON
01 05 00 01 00 00 9C 0A No. 1 relay off
01 05 00 02 FF 00 2D FA No. 2 relay ON
01 05 00 02 00 00 6C 0A No. 2 relay off


Switch all

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 off
01 0F 00 00 00 08 01 FF BE D5 Full on
01 01 00 00 00 08 BE D5 Send : Read all relay states
01 01 01 00 51 88 Return : Relay fully closed
01 01 01 03 11 89 Return : All relays are 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[edit]

Specifications:

 *   RS485 communication interface
 *   TTL communication interface
 *   4 optocoupler isolation input
 *   4 way optocoupler isolation output
 *   A user button
 *   A user LED
 *   A power indicator
 *   A STM32F030F4 microcontroller
 *   4 relay status indicators LED lights
 *   Power supply terminal interface (12V power supply)


Modbus RTU command

Baud Rate: 9600 8 NONE 1

Hex Byte Funktion
00 06 40 00 00 01 5c 1b Setting address is: 01
00 06 40 00 00 02 1c 1a Setting address is: 02
00 03 40 00 00 01 90 1b Read address
Read the software version
00 03 00 04 00 01 c4 1a [month] broadcast read (only by one device to address all practical, easy to test)
Read the hardware version (PCB version)
00 03 00 04 00 01 c4 1a broadcast read (only by one device to address all practical, easy to test)


[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[edit]

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[edit]


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)