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TOP Server not communicating until programming software has been connected
TOP Server will not communicate with the PLC after the power has been cycled on the FX3U. The device does not respond to requests. However, after the programming software has been connected once, TOP Server will communicate with no problems. What would cause this behavior?
With Mitsubishi FX PLCs, the communications baud rate defaults to 9600. The GX Developer programming software has an auto baud rate configuration function that re-configures this baud rate based on the settings in the programming software.
With your TOP Server configured to use the same baud rate as the programming software, the baud rates will not match the settings in the FX device if the power is cycled and TOP Server will not be able to communicate.
As such, we recommend using a baud rate of 9600 for the FX devices as outlined in the TOP Server FX Serial driver help file.