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Wi-MGR User Guide
800.518.1519
4
4.2.3 Function 06: Preset Single Register & Function 16:
Preset Multiple Registers
To set the relay outputs over Modbus, first set the relay activation mode must be set to Modbus
only. Do this in the web interface, at the bottom of the Digital IO Configuration page - Chapter
3, “Digital IO Configuration Page” on page 42. The master must then send a Preset Single or
Preset Multiple Register request packet.
4.3. RTU
Framing
The example below shows a typical Query/Response from a Wi-MGR.
Slave address 2 responds to Function Code 4 with six bytes of hexadecimal data and ends with
CRC16 checksum.
Register Values:
40001 = 0000 (hex)
40002 = 0000 (hex)
40003 = 0001 (hex)
Register
Name
Description
Units
Range
30001
Digital Input 1
Digital Input 1: 1=0, 0=off
uint16
0-1
30002
Digital Input 2
Digital Input 2: 1=0, 0=off
uint16
0-1
30003
Digital Input 3
Digital Input 3: 1=0, 0=off
uint16
0-1
30004
Digital Input 4
Digital Input 4: 1=0, 0=off
uint16
0-1
Table 4.5
Read Input Registers
Register
Name
Description
Units
Range
49001
Relay K1
Relay 1 Activation: 1=active,
0=inactive
uint16
0-1
49002
Relay K2
Relay 2 Activation: 1=active,
0=inactive
uint16
0-1
Table 4.6
Preset Single and Multiple Registers
Slave
Address
Function
Code
Count Bytes
of Data
Register
Data
Msb Lsb
Register
Data
Msb Lsb
Register
Data
Msb Lsb
CRC 16
“Lsb”
CRC 16
“Msb”
02
04
06
00 00 00 00 00 01 B5
A3
Table 4.7
Response Sample
