Autonics KPN Series, User Manual For Communication

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1 Modbus RTU protocol
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1.4 Read Input Registers(Func04–04H)
Read the Binary data of Input Registers(3X reference) in Slave device.
(1) Query(Master)
Slave Address Function
Starting Address No. of Points Error Check(CRC16)
High Low High Low Low High
1Byte 1Byte 1Byte 1Byte 1Byte 1Byte 1Byte 1Byte
(2) Response(Slave)
Slave Address Function Byte Count Data Data Data
Error Check(CRC16)
Low High
1Byte 1Byte 1Byte 1Byte 1Byte 1Byte 1Byte 1Byte
If read the values of 2EA range from Input Register 300001(0000 H) to 300002(0001 H)
on Slave side(Address 17) from Master side.

Query(Master)
Slave Address Function
Starting Address No. of Points Error Check(CRC16)
High Low High Low Low High
11 H 04 H 00 H 00 H 00 H 02 H ## H ## H
If the values of
300001(0000
H
) and 300002(0001
H
) are respectively “10(
A H
)” and
“20(14
H
)”
on Slave side are respectively
.

Response(Slave)
Slave Address Function Byte Count
Data Data Error Check(CRC16)
High Low High Low Low High
11 H 04 H 04 H 00 H 0A H 00 H 14 H ## H ## H
CRC16
CRC16