Mean Well LAD Series, User Manual

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5.4.1. The basic packet structure of the UART communication protocol 3
UART communication consists of R/W byte, Data Length, Data address
bytes, Data bytes, Error check.
(1) LAD transmission frame (LAD to Controller/PC；Controller/PC to LAD)
(2) Definition description
R/W byte Data Length Data address bytes Data bytes Error check（CRC-8）
Note：Cyclic Recundancy Check (CRC) is a channel coding technology
that generates a short fixed-bit check code based on data such
as network packets or computer files, which is mainly used to
detect or verify errors that may occur after data transmission or
saving, and uses the principle of division and remainder to
detect errors.
LAD models currently use CRC-8 as a means of error detection, which is
based on the following polynomial:
X +X +X+1
8 2
Specific numerical calculations can be calculated using the checksum
calculation tool from MEANWELL, which can be consulted with local
business or technical service engineers.
Name Narrate Range
R/W byte R/W decision bit
1. Read data (0x55)
2. Write data (0xAA)
Data Length The bit is determined length of the data after the R/W 1 byte
Data address bytes The address of the data to be transmitted 2 bytes
Data bytes The content of the data to be transmitted Calculated by actual bytes
CRC-8 Transmits a data error code CRC-8
( R/W byte ~ Data bytes). Contains
1 byte
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5.4.1.4 Definition of data types
The data transmission patterns of this agreement are defined as follows:
5.4.1.5 Scratchpad Address Data Description
Controller/PC to LAD datasheet
Data type Narrate Bytes Range
U1 Unsigned char 1 0 ~ 255
U2 unsigned integer 2 0 ~ 65535
S1 signed char 1 -128 ~ 127
S2 Signed integer 2 -32768 ~ 32767
R/W
byte
Data address
bytes
The data name narrate
Numeric
range Data
type
unit
0x55 0x0010 LAD status LAD status flag read instruction - U1 -
0x0020
Principal electrical
voltage
Input voltage read instructions 0 ~ 65535 U2 -
0x0030 Load current Load current read instruction 0 ~ 65535 U2 -
0x0040 Battery voltage The total voltage of the battery
series reads the instruction 0 ~ 65535 U2 -
0x0050 Single cell battery
voltage Single-cell battery voltage read
instruction 0 ~ 65535 U2 -
0x0060 Battery
undervoltage
protection point Battery UDP point read
instructions 0 ~ 65535 U2 -
0xAA 0x0010
Standby excision
instructions
Backup removal control - U1 -
0x0020
Battery
undervoltage
protection point
Battery UTP point setting 0 ~ 65535 U2 0.01V
0x0030 Buzzer control Buzzer off control - U1 -
0x0040 Standby enable
command The main standby power is
normal when the
communication enables the
power backup control
command U1 -
Note: (1) The 0x0020 instruction written is invalid when the force startup
state is forced
(2) The written 0x0050 instructions, if connected according to the
battery detection point connection, in order to detect the battery
voltage normally, otherwise FF will be reported
(3) Write command without memory function, restore factory
settings after shutdown
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