Moxa Technologies IA5150 - Manual (Page 23)

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