About the Ethernet UDP/IP I/O Device

The Ethernet UDP/IP I/O Device for the Native Platform of V+, provides an input and an output device for sending and receiving 32-bit words via an Ethernet network connection. The protocol is UDP/IP datagram and is not stream based or TCP/IP protocol. The device can be configured to receive and transmit up to 375 32-bit words on a specific receive and transmit port. Each word must be 32-bits in length, and comply with the network byte ordering (big-endian model) arrangement. The device is executed once per Native Platform frame.

Input is relative to the Native Platform. Therefore, inputs come from a host to the Native Platform, while outputs are sent from the Native Platform to another device on the network.

The device is designed to receive and transmit single packets. (A packet is specified within UDP/IP specification) There are no provisions for multi-packet schemes. Since the Native Platform is primarily a real-time device, the host is expected to transmit the same data in the same sequence on a periodic basis for use within a V+ design.

The device is configured to receive and transmit on specific ports, and may also be configured to transmit in broadcast mode, or to a specific IP address. Also, when using both input and output devices, the output may be configured to trigger on the reception of an input packet rather than at the end of the Native Platform processing frame.

For a complete discussion on this subject, including source code for the construction of software to drive this device, see the article on Windows sockets.   This article applies primarily to 16 bit PC Microsoft applications.   The 32 bit equivalent use CSocket MFC classes.