USER MANUAL
GWR Router Series
51
Modbus Gateway settings
The serial server will perform conversion from Modbus/TCP to Modbus/RTU, allowing polling by
a Modbus/TCP master. The Modbus IPSerial Gateway carries out translation between Modbus/TCP and
Modbus/RTU. This means that Modbus serial slaves can be directly attached to the unit's serial ports
without any external protocol converters.
Click Serial Port Tab to open the Modbus Gateway configuration screen. Choose Modbus Gateway options
to configure Modbus. At the Figure 28 you can see screenshot of Modbus Gateway configuration menu.
Modbus Gateway Parameters
Label
Description
Bits per second
The unit and attached serial device, such as a modem, must agree on a speed or
baud rate to use for the serial connection. Valid baud rates are 300, 1200, 2400,
4800, 9600, 19200, 38400, 57600 or 115200.
Data bits
Indicates the number of bits in a transmitted data package. Valid data bits are:
8 and 7.
Parity
Checks for the parity bit. Valid parity are: none, even and odd. None is the
default.
Stop bits
The stop bit follows the data and parity bits in serial communication. It
indicates the end of transmission. Valid stop bits are: 1 and 2. The default is 1.
Flow control
Flow control manages data flow between devices in a network to ensure it is
processed efficiently. Too much data arriving before a device is prepared to
manage it causes lost or retransmitted data. None is the default.
TCP accept port
This field determines the TCP port number that the serial server will listen for
connections on. The value entered should be a valid TCP port number. The
default Modbus/TCP port number is 502.
Connection timeout
When this field is set to a value greater than 0, the serial server will close
connections that have had no network receive activity for longer than the
specified period.
Transmission mode
Select RTU, based on the Modbus slave equipment attached to the port.
Response timeout
This is the timeout (in milliseconds) to wait for a response from a serial slave
device before retrying the request or returning an error to the Modbus master.
Maximum number of
retries
Should no valid response be received from a Modbus slave, the value in this
field determines the number of times the serial server will retransmit request
before giving up.
Log level
Set importance level of log messages.
Reload
Click
Reload
to discard any changes and reload previous settings.
Save
Click
Save
button to save your changes back to the GWR Router and
activate/deactivate serial to Ethernet converter.
Table 17 – Modbus gateway parameters
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