Visonic MCT-211

The MCT-211 is a miniature waterproof wristband transmitter designed to be used with advanced remote control and high security alarm systems. Transmission is started by pressing the button in the center of the unit. When activated, the transmitter sends a digital identification code and an alarm code, both identifiable by compatible PowerCode type receivers. The digital identification code, assigned to each transmitter, is selected at the factory from among 16 million possible combinations, and is therefore unique and practically unreproducible.

All MCT-211 units are supplied with a wrist strap, to be worn like any wristwatch. The energy for its operation is obtained from a 3-volt lithium flat battery.
During transmission, a light diode lights up, indicating that the battery voltage exceeds 2.5 volts. If the diode blinks during transmission, the battery should be replaced immediately.
Furthermore, a transmitter whose battery has been discharged will automatically add a "discharged battery" code to the digital message sent. Compatible receivers are designed to identify this code and trigger some type of alert: audible, visual, or otherwise.