User Manual

NPort W2250/2150 Plus User’s Manual Choosing the Proper Operation Mode
4-2
Overview
NPort W2250/2150 wireless Serial Device Servers are used to network-enable traditional
RS-232/422/485 devices. 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. The Serial Device Server lets you use a computer to 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 different types of instruments. Since NPort W2250/2150 wireless 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.
In addition to providing socket access, NPort W2250/2150 also comes with a Real COM/TTY
driver that transmits all serial signals intact. This means that you can continue using existing
COM/TTY-based software, eliminating the need to invest in additional, costly 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 lets you unicast to one IP
address, or multicast to groups of IP addresses.
TCP Server Mode
In TCP Server mode, NPort W2250/2150 is configured with a unique IP:Port address on a TCP/IP
network. NPort W2250/2150 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 W2250/2150 configured for
TCP Server Mode.
2. Once the connection is established,
data can be transmitted in both
directions—from the host to the NPort
W2250/2150, and from the NPort
W2250/2150 to the host.
TCP Server Mode
Request a
connection
Proceed with
data transmission
1
2
1
2
TCP/IP
WLAN
NPort W2250
Antenna
Port 1
RS-232/422/485
Port 2
RS-232/422-485
Wireless Se
rial Device Server
W2250
Reset
Ethernet
12-48 VDC
Ready
WLAN
Serial 1
Serial 2
Serial Signal
Serial Device