Yokogawa Standalone MW100 - Manual (Page 46)

1-32
IM MW100-01E
RS-422A/485 Communication (/C3 Option)
In a multi-drop, four-wire configuration, up to thirty-two units can be connected. A
dedicated protocol and the ModbusRTU protocol are supported.
Using communication commands, you can send and receive settings, and measured and
computed values.
• Modbus Master Function (/M1 Option)
The MW100 can connect to a Modbus slave device and load measured data. The
operation is the same as the Modbus client function. Target devices (Modbus slaves)
are identified with addresses.
MW100(master)
MW100
Data from slave device
Data to slave device
Modbus slave device
Serial communication
• Modbus Slave Function
Modbus master devices can connect to other MW100s acting as Modbus slaves and
read from or write to their internal registers. The MW100 registers are the same as
those for the Modbus server function.
MW100(slave)
MW100
Data to master device
Data from master
device
Modbus master device
Modbus slave device
Serial communication
For instructions on connections, see section 2.7, “Connecting the RS-422A/485 Interface
(/C3 Option).”
RS-232 Communication (/C2 Option)
This is a point-to-point system. A dedicated protocol and the Modbus/RTU protocol are
supported.
• Using communication commands, you can send and receive settings, and measured
and computed values.
• The MW100 operates as the Modbus master or slave. For information about the
operation, see “RS-422A/485 Communications (/C3 Option).”
For instructions on connections, see section 2.8, “Connecting the RS-232 Interface (/C2
Option).”
1.3 Functions of the Main Module