Yokogawa Removable Chassis DX1000N - Manual (Page 229)

6-3
IM 04L41B01-17E
Specifications
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App
Index
6.3 Modbus Protocol Specifications
Modbus Client Function
Basic Operation
• The DX, as a Modbus client device, communicates with Modbus servers periodically
by sending commands at specified intervals.
• The Modbus client function operates independently from the Modbus master function
via the serial communication.
• The supported functions are “reading data from the input registers and hold registers
on the server” and “writing data into the hold registers on the server.”
Modbus Client Specifications
Communicate via ModbusTCP
Communication media: Ethernet 10Base-T
Read cycle:
Select from the following:
125 ms, 250 ms, 500 ms, 1 s, 2 s, 5 s, and 10 s
Connection retry: Select the reconnection interval after disconnecting the
connection after the connection wait time has elapsed from the
following:
OFF, 10 s, 20 s, 30 s, 1 min, 2 min, 5 min, 10 min, 20 min, 30
min, and 1 h
Connection timeout value: 1 min
However, when the IP address is not established with DHCP, a
communication error results immediately.
Command timeout value: 10 s
Server:
Set up to 16 servers
Supported functions: Supported Modbus client functions are as follows:
The server device must support these functions.
Function Code Function Operation
3 Read the hold register
(4XXXX, 4XXXXX)
The DX reads the hold register of the server
device into the communication input data or
external input channel.
4 Read the input register
(3XXXX, 3XXXXX)
The DX reads the input register of the server
device into the communication input data or
external input channel.
16 Write to the hold register
(4XXXX, 4XXXXX)
The DX writes the measured or computed data to
the hold register of the server device.
On Models with the PROFIBUS-DP Interface (/CP1 option)
On models with the PROFIBUS-DP interface (/CP1 option), the communication input
data for C01 to C24 (on the DX1000) or for C01 to C32 (on the DX2000) is reserved for
PROFIBUS-DP. The DX cannot load values into this received data.