The new Hitachi web controller allows you to connect various industrial and home electronic equipment to the world wide web. In fact it is a miniature PLC with built-in web server and SMTP (Simple Mail Transfer Protocol) capabilities.
Being a PLC at heart, it is programmable using standard windows ladder editor software and having six 24VDC inputs and four relay outputs it is capable of controlling a small machine in its own right. Using the built-in RS232C port the web controller can also act as just an interface between existing PLC installations and the world wide web.
The built-in web server utilises HTTPD (Hyper Text Transfer Protocol Daemon) capabilities that allows up to 16 web (html) pages to be stored within the unit. These web pages can then allow operators, managers, service engineers or anyone with the necessary access privileges to monitor, report and interact with their connected equipment from anywhere in the world through any standard internet browser running on a PC. Unlike a conventional server, its programming is stored in Flash memory and cannot be modified, so it is impervious to viruses. It can be connected directly to the Internet, protected only by its password, although if the application is critical, it is recommended that it is employed with connection to a LAN with remote access via a VPN connection, therefore only network accessible users can interact with the equipment offering additional security.
The built-in SMTP protocol allows it to send emails in response to up to 16 different triggers. Each message can be sent to up to eight different email addresses, with up to 64 characters in the subject line, up to 256 characters in the message body, and up to 3 data word address values. This allows an email to be sent anywhere in the world (or the office next door) with any desired value from the connected equipment. This could be temperature, power consumption or the number of cars that have entered a car park.
It is a compact unit which can sit easily in the palm of the hand, making it a simple add-on to any new or existing installations. It is sufficiently low cost to be of interest to all sectors of the electronic market including constructors of building alarm and security systems, pointing the way to successor products likely to be found in the average home. Typical intended applications include security, working with a camera and sensor. When the sensor detects an intruder, it can instruct the camera to capture a picture and report the event to the system administrator. It can also be used to monitor the status of point of sale activities in retail outlets while allowing the monitoring and control of refrigerators and heating systems.