Moxa Technologies 5400 Series user manual TCP Client Mode, UDP Mode, Pair Connection Mode

NPort 5400 Series User’s Manual Choosing the Proper Operation Mode

TCP Client Mode

In TCP Client mode, the NPort can actively establish a TCP connection to a pre-defined host computer when serial data arrives.

After the data has been transferred, the NPort can automatically disconnect from the host computer by using the TCP alive check time or Inactivity time settings. Refer to chapter 5 for more details.

As illustrated in the figure, data transmission proceeds as follows:

1.The NPort configured for TCP Client Mode requests a connection from the host.

2.Once the connection is established, data can be transmitted in both directions—from the host to the NPort, and from the NPort to the host.

UDP Mode

Compared to TCP communication, UDP is faster and more efficient. In UDP mode, you can multicast data from the serial device to multiple host computers, and the serial device can also receive data from multiple host computers, making this mode ideal for message display applications.

Pair Connection Mode

Pair Connection Mode employs two NPort 5400 units in tandem, and can be used to remove the

15-meter distance limitation imposed by the RS-232 interface. One NPort 5400 is connected from its RS-232 port to the COM port of a PC or other type of computer, such as a hand-held PDA, and the serial device is connected to the RS-232 port of the other NPort 5400. The two NPort 5400 units are then connected to each other with a cross-over Ethernet cable, both are connected to the same LAN, or in a more advanced setup, they communicate with each other over a WAN (i.e., through one or more routers). Pair Connection Mode transparently transfers both data and modem control signals (although it cannot transmit the DCD signal) between the two NPort device servers.

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