NPort W2150A-W4/W2250A-W4 Series User Manual
17
4.
Introduction to Operation Modes
Overview
This chapter introduces the different serial port operation modes that are available on the NPort W2150A-
W4/W2250A-W4 Series. Each serial port on the NPort is configured independently of the other ports, with its
own serial communication parameters and operation mode. The serial port’s operation mode determines
how it interacts with the network, and different modes are available to encompass a wide variety of
applications and devices.
Real COM
and
RFC2217
modes allow serial-based software to access the NPort serial port as if it were a
local serial port on a PC. These modes are appropriate when your application relies on Windows or Linux
software that was originally designed for locally attached COM or TTY devices. With these modes, you can
access your devices from the network using your existing COM/TTY-based software, without investing in
additional software.
Three different socket modes are available for user-developed socket programs:
TCP Server
,
TCP Client
,
and
UDP Server/Client
. For TCP applications, the appropriate mode depends on whether the connection
will be hosted or started from the NPort serial port or from the network. The major 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 multicasting of data to groups of IP addresses and would be suitable for
streaming media or noncritical messaging applications, such as LED message boards.
Pair Connection Slave
and
Master
modes are designed for serial-to-serial communication over Ethernet,
in order to overcome traditional limitations with serial transmission distance.
In
Ethernet Modem
mode, the NPort acts as an Ethernet modem, providing a network connection to a host
through the serial port.
Real COM Mode
Real COM mode works with NPort drivers that are
installed on a network host. COM drivers are
provided for Windows systems, and TTY drivers are
provided for Linux and UNIX systems. The driver
establishes a transparent connection to the attached
serial device by mapping a local serial port to the
NPort serial port. Real COM mode supports up to
four simultaneous connections, so multiple hosts
can collect data from the attached device at the
same time.
ATTENTION
Real COM drivers are installed and configured through NPort Windows Driver Manager.
