Tonghui TH2840 Series - Modbus Commands; Command Format

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9.2.20.6 Update Command
 Description: use the command to control the instrument to perform the upgrade operation
Command systax:
:SYST:UPDATE APP
Parameter:
Example:
:SYST:UPDATE APP ----use the command to control the instrument to call the default file in the
USB flash drive to upgrade
Note: In addition, we have the software for the host computer to control the upgrade of the
instrument, which can directly send the upgrade file from the host computer and perform the
upgrade operation without the need for a USB flash drive (convenient for customers to make the
second choice for upgrade), and the issued upgrade file is stored by default. In the internal storage
of the instrument, such as update2840.sec, considering that the later upgrade file may be relatively
large, the user can delete this file periodically.
9.3 Modbus commands
9.3.1 Command format
The command format is the internal version 2.0 standard, please refer to the following description
for details:
9.3.1.1 Sending format
Instrument
address
Function
code
High
address
Low
address
High
registers
Low
registers
Total
number
of bytes
Data
byte 1
…
…
Data
byte n
CRC
Low
CRC
High
 Return format
Instrument
address
Function
code
High
address
Low
address
High
registers
Low
registers
CRC
Low
CRC
High
a) Instrument address
It refers to the local address of the instrument, which can be set in the bus address of the
instrument's system setting interface. The value range is: 1~31
b) Function code: 0x10
This command can write one data or multiple data, so its code is: 0x10
c) High address and low address
It refers to the storage address of the data in the instrument, which can be a real storage address
or a mapped address.
d) High registers and low registers
It indicates that the number of registers written in this operation and the size of each register is