You’ve surely heard of intercom systems and PA/GA systems. But how are they exactly defined? And what are the differences? This article compares both concepts and focuses on the main differences.

Intercom

Intercom systems are mainly used to support process-related voice communication in industrial environments. You have either a pre-defined subscriber to which you establish a voice connection via keypress or you reach any subscriber by dialing the corresponding call number.

Two-way Communication

For intercom systems, the most common type of voice connection used is the two-way connection (also called intercom connection). Both subscribers can speak and listen alternately, but not simultaneously. Here, the push-to-talk method is used. You press a key first and then you speak. Only after you release the speak key, the other subscriber can answer. This way, you achieve a coordinated and disciplined interaction between the subscribers ensuring a clear and safe communication that is especially important in
safety-relevant areas. You can directly inform pre-defined employees about important work instructions by making brief announcements or simply communicate the next process steps.

Duplex Communication and Conferences

Besides the typical two-way connection, you can also communicate in duplex mode or use the conference function to speak to several subscribers.

PA/GA

PA/GA systems (Public Address/General Alarm) are used everywhere you need to instantly notify people about emergency situations and to effectively evacuate them from dangerous areas. The alarms can be triggered via manual call points or via intercom stations. You can also connect PA/GA systems to fire detection and emergency notification systems via potential-free contacts or digital interfaces. As soon as they detect a fire or gas leak, the PA/GA system automatically triggers an alarm and initiates the evacuation, for example. In all danger areas affected, electronically stored alarm tones and voice messages are transmitted through speakers – in several languages if required.

Voice-over Alarm

Authorized security staff and emergency services can make live voice announcements overwriting the current alarm (voice-over alarm) to inform individuals affected about special dangerous situations and to safely evacuate them. The current alarm is interrupted for the duration of the live announcement and then continues.

Visual Signal Devices and Control Signals

Acoustic alarm signaling can be combined with visual signal devices such as warning beacons or LED displays to draw attention and make orientation easier in an emergency situation. Further, you can activate ventilation systems or open and close doors via control signals.

Zoning

Usually, the danger areas are divided into several zones. You can define the warning sequence for each zone separately. Zones can then be combined to superior groups, so that you either evacuate an individual zone or several zones at once.

All-in-one – INDUSTRONIC Makes It Easy

You see the differences: Intercom systems focus on process-oriented, bi-directional communication, whereas PA/GA systems
are used for unidirectional communication to quickly inform a large number of people in order to protect and save human lives in case of emergencies. But both concepts can be combined effectively to provide communication and alarm solutions. With the INTRON-D plus system INDUSTRONIC integrates both concepts corresponding to the requirements of the customer.

It’s More Than Voice Transmission

Modern Intercom and PA/GA systems such as the INTRON-D plus are no longer used exclusively for voice transmission purposes. They also carry out signaling tasks (e.g. fault and system status indication) or support processes in control rooms (e.g. open doors, activate cameras). As they offer numerous interfaces they can be easily connected to other systems or integrated into existing network structures.