03(0 X 03) Read The Holding Registers (Readback Ao S ) - ICPDAS ECAT-2610 User Manual

EtherCAT to Modbus RTU Gateway
03(0x03) Read the Holding Registers (Readback AOs)
This function code is used to readback either the current values in the holding registers or the
analog output value.
[Request]
Byte Description
00 Net ID (Station Number)
01 Function Code
02-03
Starting AO 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 0x03
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 to 247
1 Byte
0x03
1 Byte
Byte Count of the Response
1 Byte
(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 0x83
Refer to the Modbus Standard Specifications for
1 Byte
more details
Value
Value
Value
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