When you need a way for clients, students, employees, or anyone else to communicate with you from distant areas of your campus or property, a callbox or call box is one way to do it. A call box is a box made of metal or fiberglass that contains electronic circuitry that enables someone to press a button or pick up a handset and call a central location for assistance. Some call boxes also allow calling a portable radio so that assistance can be mobile. Today the Wireless Calling System is very important.

There are two main types of callbox units available, wired and wireless. A wired callbox involves running a cable to it from the central location. This guide is about the other kind, the wireless units.

The benefit of a wireless callbox is that you save money by not having to do trenching and running expensive cable to the unit. You also don't have to pay any air-time or telephone service fees with these wireless systems. As mentioned, another benefit is that since the unit is wireless, people monitoring the units can carry handheld radios that communicate with the callbox. That allows your monitoring people to be mobile.

The range of these units is several miles, which can be extended by adding an external antenna. Some units can use radio repeaters to extend this range even more.

If you need to remotely control gates, magnetic door locks, or barrier arms from your portable 2-way radio or desktop base station intercom, then select a unit that has this capability. With this ability you can let someone in a gate or door when they call you. There are units that also let you turn on a strobe light at the callbox location to help draw attention to it.

Another useful feature is the ability for call boxes to store a voice message that is played when someone presses its button. This could be a message that gives the caller specific instructions on what to do. These units can also send a second and different voice message alert to the monitoring central location or portable radios. This message could give the call boxes location or it could be an emergency message of some type.

By adding a motion detector or some other detection device, you can be alerted when that detection device is activated. Some call boxes will send either a tone alert or a custom voice alert when the detection sensor status changes. If this voice message is not immediately answered, the alert message is resent multiple times.

If you are running your system on battery power, you need a unit that has battery conservation mode. In this mode, only the absolute necessities for operation are powered, and the unit can not accept calls to it; it can only make calls. You can attach an external sensor to automatically put the unit into full power mode when someone is detected near the box. This will allow you to make a call to it.

Related readings: Video Door Phone System  IP Network Intercom System