Name
Description
Value range
Use HW
handshaking
(CTS/RTS)
Enables CTS/RTS handshaking if set to “Yes”.
No, Yes
Gateway
mode
Gateway
mode
If set to “Network master to serial slaves”, the slaves are on the
serial side.
Network master
to serial slaves
Protocols
Serial protocol
Defines the Modbus protocol that serial devices use in serial
communication. The possible settings are Modbus RTU protocol
and Modbus ASCII protocol. ModbusRTU is recommended
because it is more efficient.
ModbusRTU,
ModbusASCII
Network
protocol
Defines the TCP/IP and Modbus protocol used on network
communication. Possible protocols are Modbus TCP protocol
over TCP, Modbus RTU protocol over TCP, Modbus RTU
protocol over UDP, and Modbus ASCII protocol over UDP.
ModbusTCP,
ModbusRTU
over TCP,
ModbusRTU
over UDP,
ModbusASCII
over TCP,
ModbusASCII
over UDP
Framing
Slave
response
timeout
Defines the time in microseconds (millionths of a second) how
long the device waits for the response from a Modbus slave. If
the response is not received, the device can generate and return
a Modbus gateway exception. The reply timeout of the Modbus
master must be greater than the gateway device timeout.
Otherwise, the flow of request-reply communication is violated.
The device does not accept a new request before the reply from
the slave is received or the reply timeout is elapsed. The delays
in network communication can vary especially in wireless
networks. When the slaves are located on the network side, ping
or another method should be used to estimate the delay packets
spend on network.
0...90 000 000
(0...90
seconds)
Inter-frame
timeout
Defines the idle time in microseconds (millionths of a second)
that marks the end of Modbus frame in serial communication. If
the value is zero, the device uses the standard 4 character time.
The recommendation is to use a value as small as possible to
speed up communication and increase the value if problems
arise. Some PC programs can insert unexpected delays
between serial characters.
0...2 000 000
(0...2 seconds)
Exceptions
Generate
gateway
exceptions
Defines if the device generates and returns a Modbus gateway
exception message to the master if no valid reply is not received
from the slave. If set to “Yes”, the generation of exceptions is
enabled. This functionality is useful for debugging.
No, Yes
Pass gateway
exceptions
If set to “Yes”, gateway exception replies from the slave side are
passed to the master. If set to “No”, the replies are filtered away.
No, Yes
Network
server settings
Table continues on next page
Section 10
1MRS758458 F
Modbus application settings
46
ARR600
User Manual