HA7Net - Ethernet 1-Wire Host Adapter

The HA7Net is a low-cost Ethernet to 1-Wire interface designed to simplify the process of integrating distributed 1-Wire / iButton* networks into your application or system. The HA7Net allows end users to enjoy easy remote access to their 1-Wire sensors and devices. Likewise, integrators and OEMs can substantially decrease development time and installation costs associated with deploying systems based on Dallas Semiconductor 1-Wire technologies.

High-Level Device Support
The HA7Net supports a variety of 1-Wire devices at a high level. For example, reading the current temperature from a DS18S20 doesn't require the user to learn the details of reading and parsing scratchpads. Instead, you simply ask the HA7Net for the current temperature and it handles all of the required low-level communications for you. 1-Wire devices which are currently supported at a high-level include:

We continually work to add high-level support for additional 1-Wire devices, and we periodically make firmware upgrades available for download on our technical support website.

The HA7Net provides a robust low-level command set supporting operations ranging from reading CRC validated TMEX UDP records to wiggling the 1-Wire bus on and off 1 bit at a time. This means that you can talk to any 1-Wire device manufactured by Dallas Semiconductor, whether the HA7Net provides high-level support for that particular device or not. For a complete discussion of the low-level command set, please refer to the HA7Net Users Manual.

The HA7Net features remotely upgradeable firmware. We periodically** release updated firmware with additional features that you may want to install onto your HA7Net. If you can access your HA7Net via the network, then you can upgrade its firmware without having to physically visit it or uninstall it from its deployed location.

Primary communication with the HA7Net is accomplished via the HTTP protocol, with optional 128 bit SSL data encryption. The actual data is exchanged in the form of html documents which have been designed to accommodate both human readability and 100% reliable machine parsing. This is accomplished through the use of unique, predictably named form fields that can be automatically parsed by most DOM parsers, or easily digested via regular expressions on lighter weight platforms. Data is passed to the HA7Net in the form of parameters placed in the URL. Since the result pages are human readable, both proof of concept and integration times are reduced as you can effectively interact with 1-Wire devices via the HA7Net using a standard web browser.

The HA7Net will allow you to use industry standard Ethernet products (switches, hubs, etc.) to build out the backbone of your 1-Wire based sensor / control system. This provides several important benefits: First, 1-Wire networks can be easily distributed over great distances without having to deal with the challenges associated with the installation of physically large 1-Wire networks. By designing your sensor networks in a distributed star topology, the individual 1-Wire MicroLans can be kept to a smaller physical size, thereby improving reliability and decreasing installation costs. Second, since the HA7Net communicates via TCP/IP over standard Ethernet, you can take advantage of existing corporate LANs, the Internet, and in-house MIS expertise for building out and maintaining the backbone of your sensor network. Another advantage is the number of readily available libraries and developer tools which are widely available for common platforms, and can be used to communicate with the HA7Net.

Additionally, a complete debugging / logging facility is provided via a built-in telnet server. A multicast listener has also been integrated to provide ease of discovery in dynamically configured networks.

The HA7Net can perform Search and Family search functions making it easy to acquire the unique 64 bit serial numbers of all connected devices. Many sensor devices require that extra power be delivered during periods of data conversions (DS1920 and DS1820 temperature sensors for example). The HA7Net automatically provides the extra current these devices require with a built in smart strong-pull-up. Dallas Semiconductor iButtons which store data in TMEX Touch Memory File format can be read or written with simple commands. The HA7Net will automatically generate and check the CRC16 error checks from Touch Memory File records. For a complete list of the 1-Wire commands supported, please refer to the API reference in the HA7Net user's manual.

* iButton and 1-Wire are registered trademarks of Dallas Semiconductor Corporation. TMEX is a trademark of Dallas Semiconductor Corporation.

** The HA7Net's firmware is no longer being actively developed, but the other EDS Ethernet adapters (OW-SERVER and TC-SERVER) are being further developed.