Banner DXMR90-X1 Series, Instruction Manual

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May 09, 2023
DXMR90-X1 Series Controller Instruction Manual
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Modbus Operation
All Modbus transactions are managed by a central Modbus engine.
If there are Modbus messages intended for a Modbus slave that doesn't exist, the Modbus engine waits for a response until
the timeout period is expired. This slows down the Modbus polling loop for read and write operations. Each Master port is
running its own modbus engine; timeouts on one port will not affect the other ports.
Verify all Modbus read and write operations are intended for Modbus slave devices that are in the network.
Modbus Communication Timeouts
A Modbus timeout is the amount of time a Modbus slave is given to return an acknowledgment of a message sent by the
Modbus master. If the Modbus master waits for the timeout period and no response is seen, the Modbus master considers it
a lost message and continues on to the next operation.
The timeout parameter is simple to set for Modbus devices directly connected to the DXMR90-X1. Special considerations
need to be made to set the timeout parameter when the DXMR90-X1 is communicating to an external Modbus device
through a serial data radio. In general, longer timeouts may be required to ensure the data is sent and received.
Configure controllers operating wireless networks to allow for enough time for hardware transmission retries. Set the Commu-
nications Timeout parameter to cover the expected time for messages to be sent throughout the wireless network. For
the DXMR90-X1 , the Communications Timeout parameter is the maximum amount of time the DXMR90-X1 should wait after
a request is sent until the response message is received from the Modbus slave device. Use the DXM Configuration Soft-
ware to set the timeout parameter on the Register Mapping › RTU › RTU Configuration screen.
The default setting for the timeout parameter is 5 seconds.
Modbus TCP Client
The DXMR90-X1 can operate as a Modbus TCP client on Ethernet. Users may define up to five socket connections for Mod-
bus TCP server devices to read Modbus register data over Ethernet. Use the DXM Configuration Software to define and con-
figure Modbus TCP client communications with other Modbus TCP servers.
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