ATIM_ACW-DINRSM_UG_EN_V2.8
25
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In case of requests:
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0x0F = Function code 0x0F, Write Coils (Exclusively available on LoRaWAN version)
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0x10 = Function code 0x10, Write Holding Registers (Exclusively available on LoRaWAN version)
The size includes, in addition, the number of extra octets representing the number of registers/bits to
force. It can therefore vary from 7 to 10.
As the global size will necessarily exceed 8 octets (from 9 to 12 octets), these two writing requests will not
be available on Sigfox versions.
@Modbus slave - Octet 2:
This parameter deals with the Modbus ID or the Modbus slave address.
Function code - Octet 5:
The possible values for the function code are:
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0x01 = Function code 0x01, Read Coils.
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0x02 = Function code 0x02, Read Discrete Inputs.
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0x03 = Function code 0x03, Read Holding Registers.
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0x04 = Function code 0x04, Read Input Registers
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0x0F = Function code 0x0F, Write Coils (Exclusively available on LoRaWAN version)
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0x10 = Function code 0x10, Write Holding Registers (Exclusively available on LoRaWAN version)
@Reg/bit - Octet 6 and Octet 7:
Address of the first register/bit of the slave to read or write. The octet 6 deals with the least significant byte
of the value and the octet 7 deals with the most significant byte of the value.
Number of registers/bits - Octet 8:
This parameter deals with the number of registers or bits to read or write.
In case of function codes 0x0F, Write Coils and 0x10, Write Holding Registers this parameter is limited in size,
because the downlink can not exceed 12 octets. (Requests 0x0F, Write Coils and 0x10, Write Holding
Registers are exclusively available on LoRaWAN versions)
This deals to:
⚫
For the function code 0x0F: Number of bits
≤
32bits
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For the function code 0x10: Number of registers
≤
2 registers (1 register = 2 octets)
