0X02) Reading The Discrete Inputs - ICP DAS USA ZT-2017 User Manual

6.3.4

02 (0x02) Reading the Discrete Inputs

Description
This function code is used to read the current digital input values from the
ZT-2000 I/O 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-2017 and ZT-2017C AI Series User Manual, Version 1.0.1
Copyright © 2012 by ICP DAS Co., Ltd. All Rights Reserved.
Length Value
1 1 to 247
1 0x02
2 See Section 6.3.1 for details
2 0x0001 to 0x0020
Length Value
1 1 to 247
1 0x02
Byte Count of the Response
1
(B=(Bit Count + 7)/8)
B (Bit Values)
Length Value
1 1 to 247
1 0x82
Refer to the Modbus standard for more
1
details
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