Modbus Register; 0X01) Read Coils - ICP DAS USA ZT-257 Series Quick Start Manual

Modbus Register

5.3

5.3.1. 01 (0x01) Read Coils

This function code is used to read the temporary Digital Output values from a range of
virtual/logical channels on the ZT-257x module.
Request
Byte Description
00 Address
01 Function Code
Starting Channel
02-03 Number or
Address Mapping
Output Channel
04-05
Number or Bit Count
Response
Byte Description
00 Address
01 Function Code
02 Byte Count
03 Bit Values
Error Response
Byte Description
00 Address
01 Function Code
02 Exception Code
ICP DAS, ZT-257x DIO Data Concentrator Quick Start Guide, v1.0
Length
1
1
2
2
Length
1
1
1
B
Length
1
1
1
Copyright © 2016, by ICP DAS Co., LTD. All Rights Reserved
Value
0x01 to 0xF7 (1 to 247)
0x01
DO (Temporary Output)
DI (Temporary Input)
Safe Value
Check Router Alive
Channel <See Note 1>
0x0001 to 0x0118 (Bit Count)
Value
0x01 to 0xF7 (1 to 247)
0x01
The Byte Count of the Response
[B = (Bit Count + 7)/8]
(Bit Values)
Value
0x01 to 0xF7 (1 to 247)
0x81
Refer to the Modbus standard for more details
0x0000 to 0x0117
0x0200 to 0x0317
0x0400 to 0x0517
0x0601 to 0x061F
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