The DA-4PM/0F2 chassis occupies two rack height units and a safety relay for messages and a program input (RSAP-F2) can be added as an option to each power module. The safety relay is the one that allows live announcements to be broadcast if there are attenuators in the installation, and the program input admits a music signal, for example, which will be replaced by the live announcement as it has the highest priority. With this option, each loudspeaker zone can be custom configured: the zones without music and without attenuators will go without the RSAP-F2 relay, and those with music and/or attenuators will incorporate it. The chassis has four switches on the front to turn each power module on and off individually.
The DA-4PM/0 chassis occupies only one rack height unit and is designed primarily for voice alarm systems. For this reason, it does not have front switches to avoid improper disconnections and, most importantly, it allows the change of a power module, or the expansion of the stage, with the system running (hot-swap), an added security measure that facilitates technical maintenance tasks while ensuring system operation 100% of the time. It is a device designed for integration with the COMPACT and OPTIMAX2 voice alarm and evacuation systems, although it works autonomously and can be installed as a multichannel amplifier in combination with any device that provides the audio signal.