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9. Modbus Communication
Modbus is a communications protocol developed by Modicon.
Using this, communication with Modbus enabled devices can be performed without special programs.
With the checkweigher, Modbus RTU (a serial communication protocol using the RS-232 or RS-485) and Modbus
TCP (which serial communication is expanded to TCP/IP) can be used.
Using Modbus communication, setting changes, reading the summary data, writing DI and reading the DO status can
be performed.
Note:
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Only the settings of the product selected for weighing can be changed by Modbus communication.
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When group numbers or product numbers are changed by Modbus communication, the new settings will be read.
When the number has not been registered, it will be registered before reading.
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When group numbers or product numbers are changed by Modbus communication, several seconds are
required to confirm the changes.
・
In Modbus communication, the simultaneity of data is not guaranteed.
When, for example, all the data of the address map are read, the time of those data may not be the same.
For weighing results, data for each weighing may not necessarily read.
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When data is written to the holding register by Modbus communication, the information bar on the upper side of
the screen flashes in green.
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For connection when Modbus/TCP or Modbus/RTU is used, refer to “7.2. Connecting a LAN” and “7.4.
Connecting to the Serial Interface.”
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To use Modbus/TCP, the LAN setting of the checkweigher is required. For details, refer to “5.4. Setting LAN.”
