Modbus RTU
／
TCP Server User Manual for LinPAC / LinCon
Ver : 1.0 (
2009.04)
9
L2
2-2. Function Code 02
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Read Discrete Inputs (1xxxx)
This function code is used to read the ON/OFF status of DIs.
Request PDU
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Device Net ID
Function code
Address Hi
Address Lo
Data Count Hi Data Count Lo
ID
02
Slot Index (1~8)
DI Address
Contiguous DI bits for query
Response PDU
Byte 0
Byte 1
Byte 2
Byte 3
～
(Byte Count + 2)
Device Net ID
Function code
Byte count = (bit count + 7) / 8
Response DI value
ID
02
Response data length
DI ON / OFF status [**]
[**] Least Significant Bit (LSB) is the first DI value.
If the data bits is not a multiple of eight, the remaining bits will be padded with
zeros.
2-3. Function Code 03
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Read Holding Registers (4xxxx)
This function code is used to read back AO settings from I-8017 and I-87017 modules.
Request PDU
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Device Net ID
Function code
Address Hi
Address Lo
Data count Hi
Data count Lo
ID
03
Slot Index (1~8)
AO Address
Contiguous AO no. for query
I-8024 Module NOTE
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The bytes of AO address are invalid for module I-8024, no matter which AO address
you specified, it only allows to read back the latest output value for response.
