Which option is NOT a permissible second communications pathway for a DACT system without AHJ approval?

Which option is NOT a permissible second communications pathway for a DACT system without AHJ approval?

• A. Two-way RF multiplex
• B. Performance-based technology
• C. One-way private radio
• D. Second telephone line

Answer: (C)

The key idea here is that a second communications pathway for a DACT system must be capable of two-way communication. That way, alarms can be transmitted and, just as important, acknowledgments or status messages can be received back to confirm what happened. A one-way private radio only sends information in one direction and cannot receive responses or status updates. That makes it unsuitable as a backup path in most setups and, without explicit AHJ-approved exceptions, not permissible as the second pathway. The other options provide bidirectional links: a two-way RF multiplex clearly supports sending and receiving data, and a second telephone line is a traditional two-way channel. Performance-based technology represents a flexible approach that can be used as a second path when the design is approved. So the option that does not fit as a permissible second pathway without AHJ approval is the one-way private radio.

The key idea here is that a second communications pathway for a DACT system must be capable of two-way communication. That way, alarms can be transmitted and, just as important, acknowledgments or status messages can be received back to confirm what happened.

A one-way private radio only sends information in one direction and cannot receive responses or status updates. That makes it unsuitable as a backup path in most setups and, without explicit AHJ-approved exceptions, not permissible as the second pathway.

The other options provide bidirectional links: a two-way RF multiplex clearly supports sending and receiving data, and a second telephone line is a traditional two-way channel. Performance-based technology represents a flexible approach that can be used as a second path when the design is approved. So the option that does not fit as a permissible second pathway without AHJ approval is the one-way private radio.