0X01) Read The Status Of The Coils (Read Do Readback Values) - ICPDAS ET-2268 CR User Manual

ET-2200 Series Ethernet I/O Modules
6.2.1 01(0x01) Read the Status of the Coils
(Read DO Readback values)
This function code is used to read either the current status of the coils or the current Digital
Output readback value from the ET-2200 series module.
[Request]
Byte Description
00 Net ID (Station Number)
01 Function Code
02-03 Starting DO Address
04-05 Number of Points (Channels)
[Response]
Byte Description
00 Net ID (Station Number)
01 Function Code
02 Byte Count
03 Data
[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 0x01
Refer to Section
Table" to find the address.
2 Bytes
Byte 02 = high byte
Byte 03 = low byte
Byte 04 = high byte
2 Bytes
Byte 05 = low byte
Size
1 Byte 1 to 247
1 Byte 0x01
Byte Count of the Response
1 Byte
( n = (Points+7)/8 )
n= 1; Byte 03 = data bit 7 to 0
n= 2; Byte 04 = data bit 15 to 8
n Bytes
.......
n= m; Byte m+2 = data bit (8m-1) to 8(m-1)
Size
1 Byte 1 to 247
1 Byte 0x81
Refer to the Modbus Standard Specifications for
1 Byte
more details
Value
6.3 or 6.4 "Modbus Register
Value
Value
-139 -