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Product Support

Product FAQs


I am able to ping and telnet my NPort from a host computer, but I am not able to connect to the NPort using my TCP client program. What could be the problem?


Use the following steps to check the network environment settings and NPort settings:

  1. Connect to your NPort’s web UI by entering the IP address of the NPort in a browser and make sure that your NPort is in the TCP Server mode.

    For example, if you are using NPort 6000 Series, go to the Serial Port Configuration > Operation Modes page. Select Socket in the drop-down menu for the Application field and then select TCP Server for the Mode field.

  2. Make sure that the listening TCP Port of your NPort matches the destination port of your TCP client program.
  3. If your host computer (host) and NPort are in a DHCP environment, do the following:
    1. Assign a fixed IP address to the NPort and your host and make sure that they are in the same network subnet.
    2. If the IP address of the NPort is unknown or the NPort is not in the same subnet as the host, install the Device Search Utility/NPort Search Utility and click on the Search button to find all NPorts that are connected to the host or on the same LAN.
  4. If you are using the DE-311/211, make sure that DIP SW1 is switched off for data communication.
  5. Connect to the NPort’s web UI and check if the destination ports of your TCP client program are occupied.

    For example, if you are using the NPort 6000 Series, go to the Log, Monitoring and Warning > System Monitoring > System Status > Network Connections page and make sure the destination ports of your TCP client program (or the local TCP port of your NPort) are in the LISTEN state.

  6. Ensure that the IP address of your host is included in the accessible IP list of the NPort.

    For example, in the NPort 6000 Series, you can go to the System Configuration > Accessible IP List page to check the accessible IP list and include the IP address of the host, if it is not already included.

  7. Ensure that the filtering rules in your firewall do not restrict the destination TCP ports of the TCP client program (or the local TCP ports of your NPort).

Relevant Products

CN2600 Series · MiiNePort E1 Series · MiiNePort E2 Series · MiiNePort E3 Series · MiiNePort W1 Series · NE-4100 Series · NE-4100-ST Series · NPort 5000AI-M12 Series · NPort 5100 Series · NPort 5100A Series · NPort 5200 Series · NPort 5200A Series · NPort 5400 Series · NPort 5600 Series · NPort 5600-DT Series · NPort 5600-DTL Series · NPort 6100/6200 Series · NPort 6400/6600 Series · NPort Express Series · NPort IA5000A Series · NPort IA5000A-I/O Series · NPort IAW5000A-I/O Series · NPort P5150A Series · NPort S8000 Series · NPort W2150A/W2250A Series ·

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