User manual

NPort 5000AI-M12 Series Choosing the Proper Operation Mode
4-2
Overview
NPort 5000AI-M12 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 5000AI-M12 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 5000AI-M12 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 5000AI-M12 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
5000AI-M12 comes equipped with COM drivers that
work with
Windows 98/ME/NT/2000, Windows
XP/2003/Vista/2008/7
x86/x64 systems, and also TTY
drivers for Linux
or Unix systems. The driver establishes a
transparent connection between host and serial
device by
mapping the IP:Port of the NPort
5000AI-M12’s serial port
to a local COM/TTY
port on the host computer. Real COM
Mode also
supports up to 8 simultaneous connections, so
that
multiple hosts can collect data from the same serial
device at the same time.
ATTENTION
The driver used for Real COM Mode comes with the NPort Administrator.
The driver is installed automatically
on your computer when you install NPort 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 5000AI-M12 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 5000AI-M12’s serial ports.