04(0 X 04) Read The Input Registers (Read Ai S ) - ICPDAS ECAT-2610 User Manual

EtherCAT to Modbus RTU Gateway
04(0x04) Read the Input Registers (Read AIs)
This function code is used to read either the input registers or the current analog input value.
[Request]
Byte Description
00 Net ID (Station Number)
01 Function Code
02-03 Starting AI Address
Number of 16-bit Registers
04-05
(Channels)
[Response]
Byte Description
00
Net ID (Station Number)
01
Function Code
02 Byte Count
03~ Register Values
[Error Response]
Byte Description
00
Net ID (Station Number)
01
Function Code
02
Exception Code
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Size
1 Byte 1 to 247
1 Byte 0x04
Refer to the Modbus address depends on your
slave device for more details.
2 Bytes
Byte 02 = high byte
Byte 03 = low byte
Word Count
2 Bytes Byte 04 = high byte
Byte 05 = low byte
Size
1 Byte 1 to 247
1 Byte 0x04
1 Byte Byte Count of the Response (n=Points x 2 Bytes)
Register Values
n= 2; Byte 03 = high byte
Byte 04 = low byte
.......
n Bytes n= m; Byte 03 = high byte
Byte 04 = low byte
.......
Byte m+1 = high byte
Byte m+2 = low byte
Size
1 Byte 1 to 247
1 Byte 0x84
Refer to the Modbus Standard Specifications for
1 Byte
more details.
Value
Value
Value
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