CPU core of DataLab IO/ETH with Ethernet interface is fully compatible with all I/O modules of DataLab IO system. Only the USB 2.0 interface is replaced with 10/100 Mbit Ethernet interface and the device communicates using TCP/IP protocol.

The Ethernet interface brings several advantages compared to USB:

• Distance between the device and host PC is not limited to 5 m, which is the case of USB (active extender cables can prolong USB connection, but the cable must be created from multiple 5 m segments with active repeaters). Single Ethernet cable can be up to 200 m long. Because Ethernet traffic can be easily transported by other means than twisted pair cable (e.g. wireless relay connection), the actual connection length can be much longer.

• Because the device uses TCP/IP protocol, which can be easily routed through various network, the physical distance of the device from the host PC if practically unlimited.

On the other side it is necessary to count with some disadvantages compared to USB devices:

• While the USB is designed with Plug-and-Play operation on mind (no configuration of USB devices is necessary), devices using Ethernet and TCP/IP protocol must be properly configured (IP address, network mask, address of default gateway).

  Remark:

  The DataLab IO/ETH works in the role of “network server” (the PC sends input/output requests to DataLab IO), it is necessary to define static IP address for the device. It is not possible to let the DHCP server to assign IP address automatically. The computer using the device would not be able to specify proper IP address in such case.

• The device with Ethernet interface must by powered from external power supply. While there is a possibility to use PoE (Power over Ethernet), it is necessary to use external splitter to Ethernet signals and power connector.

• DataLab IO/ETH with Ethernet interface is available only in variant for four I/O modules. Smaller devices for two and for single I/O module is available only with USB interface.

  Remark:

  The fact that DataLab IO/ETH contains 4 slots for I/O modules does not mean that all 4 slots must be occupied. Similarly like in the case of USB-based devices, it possible to use only one, two, three or all four I/O modules depending on the application requirements.

There is no difference between USB and Ethernet connected DataLab IO devices from the application point of view. It is enough to specify means of communication in the device driver parametric file. The rest of application sees no difference.

[device]
type = ethernet
ip_address = 192.168.0.3
remote_port = 10250
local_port = 40230
ip_timeout = 500
con_timeout = 500
password = 12345

The DataLab IO offers HTTP server for the configuration. No special software is used to configure the device, standard WWW browser is enough.

Because WWW server traffic handling consumes significant resources on the small device and it is also not desirable to configure the device anytime from any accessible WWW browser, the HTTP server in the device is run only when the device is turned on with Reset button pressed. Only the it is possible to set parameters through WWW browser. When the device is powered on normally, HTTP server does not run and the device responds only to requests to read and write technology signals.

One of the device configuration parameters is password. The communication between each computer and the DataLab IO/ETH device is encrypted, which eliminates unauthorized reading of technological data or controlling of the technology from other computers within a computer network.