25
ATIM_ACW-DINRSM_UG_EN_V2.8
The ACW will return the version number in the following format:
Modbus request
To achieve a Modbus request, you would need to send the below command:
Size - Byte 2
Frame size from Byte n°3.
➢
In case of requests:
−
0x01 = Function code 0x01, Read Coils.
−
0x02 = Function code 0x02, Read Discrete Inputs.
−
0x03 = Function code 0x03, Read Holding Registers.
−
0x04 = Function code 0x04, Read Input Registers
The size must match to the value of 6, because Bytes 9..12 are not necessary in case of reading requests; and the
global size of the command must not exceed 8 Bytes, in order to allow its emission through a Sigfox downlink.
➢
In case of requests:
−
0x0F = Function code 0x0F, Write Coils (Exclusively available on LoRaWAN version)
−
0x10 = Function code 0x10, Write Holding Registers (Exclusively available on LoRaWAN version)
The size includes, in addition, the number of extra Bytes representing the number of registers/bits to force. It can
therefore vary from 7 to 10.
As the global size will necessarily exceed 8 Bytes (from 9 to 12 Bytes), these two writing requests will not be
available on Sigfox versions.
@Modbus slave - Byte 2
This parameter deals with the Modbus ID or the Modbus slave address.
Description and value
Byte 1
Response to command frames: 0x07
Byte 2
‘Protocol version’ command: 0x07
Byte 3
Protocol version (LSB)
Byte 4
Protocol version (MSB)
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
Byte 8
Byte 9 .. 12
0xC1
Size
0x7F
@Modbus
Slave
Function
code
@Reg/
bit
LSB
@Reg/b
it
MSB
Number of
registers/bit
s
Value of
bits/Register
to force
