iNS-316 User Manual
Copyright
©
2022 ICP DAS CO., Ltd. All Rights Reserved.
- 49 -
7.2.4 04(0x04) Read the Input Registers (Read AI values)
This function code is used to read either the input registers or the current analog input value from
the iNS-316. These registers are also used to store the current value for the digital counter, the
number of DI channels and the number of DO channels, etc.
[Request]
Byte
Description
Size
Value
00
Net ID (Station Number)
1 Byte
1 to 247
01
Function Code
1 Byte
0x04
02-03
Starting AI Address
2 Byte
Byte 02 = high byte
Byte 03 = Low byte
04-05
Number of Registers
(Channels)
2 Byte
Word Count
Byte 04 = high byte
Byte 05 = Low byte
[Response]
Byte
Description
Size
Value
00
Net ID (Station Number)
1 Byte
1 to 247
01
Function Code
1 Byte
0x04
02
Byte Count
1 Byte
Byte Count of the Response
( n = Points x 2 Byte )
03
Register Values
n Byte
n= 1; Byte 03 = high byte
n= 2; Byte 04 = Low byte
.......
n= m; Byte m+1 = high byte
Byte m+2 = Low byte
[Error Response]
Byte
Description
Size
Value
00
Net ID (Station Number)
1 Byte
1 to 247
01
Function Code
1 Byte
0x84
02
Exception Code
1 Byte
Refer to the Modbus Standard
Specifications for more details
