Moxa Technologies IA5150 User Manual

Page of 108
NPort IA5150/5250 Series User’s Manual 
Choosing the Proper Operation Mode 
 
4-2
Overview 
NPort IA5150/5250 Serial Device Servers network-enable traditional RS-232/422/485 devices, in 
which a Serial Device Server is a tiny computer equipped with a CPU, real-time OS, and TCP/IP 
protocols that can bi-directionally translate data between the serial and Ethernet formats. Your 
computer can access, manage, and configure remote facilities and equipment over the Internet 
from anywhere in the world. 
Traditional SCADA and data collection systems rely on serial ports (RS-232/422/485) to collect 
data from various kinds of instruments. Since NPort IA5150/5250 Serial Device Servers 
network-enable instruments equipped with an RS-232/422/485 communication port, your SCADA 
and data collection system will be able to access all instruments connected to a standard TCP/IP 
network, regardless of whether the devices are used locally or at a remote site. 
NPort IA5150/5250 is an external IP-based network device that allows you to expand the number 
of serial ports for a host computer on demand. As long as your host computer supports the TCP/IP 
protocol, you won’t be limited by the host computer’s bus limitation (such as ISA or PCI), or lack 
of drivers for various operating systems. 
In addition to providing socket access, NPort IA5150/5250 also comes with a Real COM/TTY 
driver that transmits all serial signals intact. This means that your existing COM/TTY-based 
software can be preserved, without needing to invest in additional software. 
Three different Socket Modes are available: TCP Server, TCP Client, and UDP Server/Client. The 
main difference between the TCP and UDP protocols is that TCP guarantees delivery of data by 
requiring the recipient to send an acknowledgement to the sender. UDP does not require this type 
of verification, making it possible to offer speedier delivery. UDP also allows unicast or multicast 
of data to only one IP or groups of IP addresses. 
 
 
Real COM Mode 
NPort IA5150/5250 comes equipped with COM 
drivers that work with Windows 
95/98/ME/NT/2000/XP systems, and also TTY 
drivers for Linux systems. The driver establishes a 
transparent connection between host and serial 
device by mapping the IP:Port of the NPort 
IA5150/5250’s serial port to a local COM/TTY 
port on the host computer. Real COM Mode also 
supports up to 4 simultaneous connections, so that 
multiple hosts can collect data from the same 
serial device at the same time. 
RS-232/422/485
Driver Mode
COM3=IP Port
Device
TCP/IP
Ethernet
Real COM Mode