Moxa Technologies user manual TCP Server Mode, Overview, NE-4100 Series User’s Manual

NE-4100 Series User’s Manual Choosing the Proper Operation Mode

Overview

NE-4100 Series Embedded Network Enablers act as a bridge to connect your serial devices to the Ethernet. The built-in TCP/IP stack saves you a lot of time on programming networking protocols. One simple step allows you to choose the proper operating mode, and then use your computer to access, manage, and configure your serial device 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 NE-4100 Series Network Enablers are equipped with the ability to convert between serial and Ethernet signals, your SCADA and data collection system will be able to access all devices connected to a standard TCP/IP network, regardless of whether the devices are used locally or at a remote site.

Three different socket modes—TCP Server, TCP Client, and UDP Server/Client—and one real COM mode are available. 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 multicasting of data to groups of IP addresses.

NOTE Pictures in this Chapter use NE-4110S as an example.

TCP Server Mode

In TCP Server mode, NE-4100 provides a unique IP:Port address on a TCP/IP network. NE-4100 Series boards wait 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 connects to the NE-4100 Series boards configured for TCP Server Mode.

2.Once the connection is established, data can be transmitted in both directions—from the host to the NE-4100 Series boards, and from the NE-4100 Series boards to the host.

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