Siemens Data Key Receiver

The Fiber Optic port consists of two fiber optic receivers, logically connected to the NEMA Port 3. Data received on either fiber optic receiver is sent to the controller, as well as the other fiber optic transmitter. The Fiber Optic acts as a repeater, receiving controller data, plus boosting and retransmitting the signal to the next controller. If received message is destined for this controller, the controller reply is transmitted simultaneously on both fiber optic transmitters.

The data key is used by the EPAC m50 series software to hold the intersection data. Once the intersection data is entered through the front panel key pad, or by download, the intersection data can then be transferred to the data key.  The data key may then be inserted in the EPAC M50 series controller indefinitely while the intersection is being controlled. If the controller is knocked down, the data key can then be removed from the damaged controller and inserted into the replacement controller to transfer the intersection data.

Data key is not used to hold the EPAC intersection control software. Intersection control software may be reloaded via laptop, PC or PDA via RS-232 connector or via Ethernet.


All of Yunex controllers and accessories are built with the highest standards in quality and manufacturing. With a long standing history of technological innovations, well renowned customer service, and high quality products and services, Yunex is the leader in traffic technology products and solutions. For more information on their product line see their website at