Cotek AD-1500 - Read Coils Registers; Modbus Function Code Read Holding Registers (0 X03)

5
Response Frame:
length
Description
Slave Address
1 Byte
00XA0 (AD Default Address)
Function Code
1 Byte
0 0x01
Byte count
1 Byte
2 2 * N (N = Quantity of Register in Request)
Register Value
N*2 Bytes
Data
CRC LSB
1 Byte
CRC MSB
1 Byte
1-7. Read Coils Registers
FUNC
CODE
Starting
Address
Description
Write number
of byte
CMD AND RESPONSE
Value
1
0X0001
Read the
power ON/Off
status
2
A0 01 00 01 00 01 B5 7B
A0 01 02 00 00 04 25
1: power on
0: power off
1-8. Modbus Function Code Read Holding Registers
(0x03)
This function code is used to read the contents of a contiguous block of holding
registers in a remote device. The Request PDU specifies the starting register
address and the number of registers. In the PDU Registers are addressed starting at
zero. Therefore registers numbered 1-4 are addressed as 0-3
The register data in the response message are packed as two bytes per register,
with the binary contents right justified within each byte. For each register, the first
byte contains the high order bits and the second contains the low order bits.