0X03) Read The Holding Registers (Read Ao Readback Values ) - ICPDAS ET-2268 CR User Manual

ET-2200 Series Ethernet I/O Modules
6.2.3 03(0x03) Read the Holding Registers
(Read AO Readback values )
This function code is used to read back either the current values in the holding registers or the Analog
Output value from the ET-2200 series module. These registers are also used to store the preset
values for the Digital Counter, the host watchdog timer, the module name, the TCP timeout, etc.
[
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 Section
2 Bytes Table" to find the address...
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 0x03
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 m+1 = high byte
Byte m+2 = low byte
Size
1 Byte 1 to 247
1 Byte 0x83
Refer to the Modbus Standard Specifications
1 Byte
for more details
Value
6.3 or 6.4 "Modbus Register
Value
Value
-143 -