Moxa Technologies 5400 Series Benutzerhandbuch

 

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. 

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 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.