Moxa Technologies IA5150 User Manual

Page of 108
NPort IA5150/5250 Series User’s Manual 
Choosing the Proper Operation Mode 
 
4-3
 
ATTENTION 
The driver used for Real COM Mode comes with the NPort IA5150/5250 NPort Administrator. 
The driver is installed automatically on your computer when you install NPort IA5150/5250 
Administration Suite.
 
 
One of the major conveniences of using Real COM Mode is that Real COM Mode allows users to 
continue using RS-232/422/485 serial communications software that was written for pure serial 
communications applications. The driver intercepts data sent to the host’s COM port, packs it into 
a TCP/IP packet, and then redirects it through the host’s Ethernet card. At the other end of the 
connection, the NPort IA5150/5250 accepts the Ethernet frame, unpacks the TCP/IP packet, and 
then transparently sends it to the appropriate serial device attached to one of the NPort 
IA5150/5250’s serial ports. 
 
ATTENTION 
Real COM Mode allows several hosts to have access control over the same NPort IA5150/5250. 
The driver that comes with your NPort IA5150/5250 controls host access to attached serial 
devices by checking the host’s IP address. Refer to Accessible IP Settings in Chapter 5 for more 
details.
 
 
TCP Server Mode 
In TCP Server mode, NPort IA5150/5250 is 
configured with a unique IP:Port address on a 
TCP/IP network. NPort IA5150/5250 waits 
passively to be contacted by the host computer, 
allowing the host computer to establish a 
connection with and get data from the serial 
device. This operation mode also supports up to 4 
simultaneous connections, so that multiple hosts 
can collect data from the same serial device—at 
the same time. 
As illustrated in the figure, data transmission 
proceeds as follows: 
1.  The host requests a connection from the 
NPort IA5150/5250 configured for TCP 
Server Mode. 
2.  Once the connection is established, data can 
be transmitted in both directions—from the 
host to the NPort IA5150/5250, and from the 
NPort IA5150/5250 to the host. 
TCP Server Mode
1Request a
   connection
2Proceed with
   data transmission
TCP Server
RS-232/422/485
1
2
Device
TCP/IP
Ethernet