The time from off-hook to on-hook per attempt for a digital alarm communicator transmitter must not exceed how many seconds?

The time from off-hook to on-hook per attempt for a digital alarm communicator transmitter must not exceed how many seconds?

• A. 60 seconds
• B. 90 seconds
• C. 120 seconds
• D. 180 seconds

Answer: (B)

The time tested here is the maximum length of one dialing attempt by a digital alarm communicator transmitter, from the moment the line is taken off-hook to when it returns on-hook. This per-attempt limit is set at 90 seconds. Keeping each call attempt within 90 seconds prevents a single alarm transmission from tying up the public telephone line for too long, which helps ensure the monitoring facility can answer and that the system can retry or switch paths if needed. If the window were longer, say 120 or 180 seconds, a line could be occupied unnecessarily during busy periods, potentially delaying other communications or causing missed transmissions. A shorter window, like 60 seconds, would risk terminating an attempt too early and failing to complete the transmission. Therefore, 90 seconds per attempt is the standard.

The time tested here is the maximum length of one dialing attempt by a digital alarm communicator transmitter, from the moment the line is taken off-hook to when it returns on-hook. This per-attempt limit is set at 90 seconds. Keeping each call attempt within 90 seconds prevents a single alarm transmission from tying up the public telephone line for too long, which helps ensure the monitoring facility can answer and that the system can retry or switch paths if needed. If the window were longer, say 120 or 180 seconds, a line could be occupied unnecessarily during busy periods, potentially delaying other communications or causing missed transmissions. A shorter window, like 60 seconds, would risk terminating an attempt too early and failing to complete the transmission. Therefore, 90 seconds per attempt is the standard.