Omron NV3Q Series, Connection Manual

Page: 114 / 145

90
Modbus (RTU Mode)
Section 10-2
10-2 Modbus (RTU Mode)
Overview of
Communications The PT is the Modbus-RTU master.
The parts on the screens of the PT read and write memory in the PLCs, which
are Modbus-RTU slaves.
With the NV3W, communications is possible with only one of the connected
PLCs. With the NV4W or NV3Q, communications is possible with up to 31
PLCs. (PT system program version 1.1 or higher is required.)
PLC Model Selection • Device setting: Start No. xxxxx0
Select Modbus (RTU Mode).
Applicable Devices
Communications Settings The following communications settings are recommended for the PT and
PLC.
■
PT Communications Settings
NV
PLC
RS-485
(Modbus-RTU Master)
(Modbus-RTU Slave)
Bit/word devices No. Comments
Bit devices Input relays 100000 to 165535
Coils 000000 to 065535
Word devices Input relays 100000 to 165535 The address must be a multi-
ple of 16.
Coils 000000 to 065535 The address must be a multi-
ple of 16.
Input registers 300000 to 365535
Holding registers 400000 to 465535
Item Setting
PLC station number 1
Baud rate 19,200 bps
Data length 8
Stop bits 1
Parity Even