I. Thou shalt place high priority on security, for hackers lurketh, thieves stealeth and employees bungleth
A Wi-Fi-enabled computer can connect to multiple networks at the same time. Your employees can give a hacker a pathway into your internal network simply by powering up a laptop. Imagine the mess an eco-terrorist could make if he didn’t like the look of your smokestack.
Even your well-intentioned employees can bring a network down, simply by blundering around in areas they shouldn’t. Don’t take chances with network security.
Most wireless systems employ industry-standard WEP (Wired Equivalent Privacy). A hacker can get around it within a few hours. Look into more powerful standards like Extensible Authentication Protocol and Tunneled Extensible Authentication Protocol.
Never assume that your industrial Ethernet products have built-in security features. At the very least, you should use inspection-type firewalls (such as packet filters) to control any access that is based on IP source address, destination address, and port number.