GE Hydran 201i Instruction Manual page 247

Hydran* 201i Instruction Manual
Modbus Date Type
Read coil status
Read discrete input status
Read holding registers
Read input register
Force single coil
Force multiple coils
Preset single holding register
Preset multiple holding registers
In order to promote the interoperability of systems, the coils and discrete inputs are
accessed as the same digital data objects. For the same reason, the input and holding
registers are also accessed through the same 16-bit data objects. An unsupported
function code addressed to the Hydran 201Ti slave returns an Illegal Function Code
exception response code of 01; see Section J.3.2 on page 252 for more details.
J.3.1.1 Read Coils (01h) / Read Discrete Inputs (02h)
This function is used to read a binary value. Up to 2,000 (07D0h) consecutive binary
can be read per request. Table J-5 shows the format of the master and slave packets.
Note: This Section demonstrates how to build and understand a 01h or 02h Modbus
request/response exchange. To read or write Hydran 201Ti's digital data values,
please refer to the subsequent Sections.
MA-033 Rev. 14.0, 12-Nov-18
Referred as
Read Binary
Read Analog
Write Binary
Write Analog
Table J - 4: Function codes
Function Code (hex)
01
02
03
04
05
0F
06
10
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