The TTI Communicator is programmed with multiple fail-safe modes of operation. These operations are either automatically or remotely activated, depending on the condition that exists.

A listing of these operations is as follows:
• Temporary Communications
• Multiple Call Routing Contingencies
• Dial Tone Break Detect Override
• Dial Tone Detect Override
• Voice Detect Override
• Microprocessor Supervisory Circuit

Temporary Communications (requires optional built-in microphone and speaker)

In the event that the handset has been vandalized and/or is inoperative, the Communicator's microphone and loud speaker can be activated by the called party, to provide a temporary means of communicating with the caller. To activate the Communicator's loud speaker and microphone, the called party enters touch-tone commands on his/her standard telephone.

Multiple Call Routing Contingencies

Calls are routed to primary and alternate locations based on the day and time of day that the calls are initiated, and/or if "busy line" or "no answer" conditions exist.

Dial Tone Break Detect Override

In the event that there is excessive noise being generated over the telephone line (Telco problem), preventing the dial tone detect circuit from properly detecting the breaking of dial tone, when a call is being placed, the Communicator can be Factory Remote programmed to ignore this condition and place the call (until phone line problem is corrected). To determine if this condition exists, extract the Communicator's diagnostic, either via the Poller or the optional On-Site Audio Verification. If a report is generated stating: "System failed, can not break dial tone... Please check phone line," or, "System failed, can not break dial tone, can not break dial tone with touch-tone... Please check phone line," contact TTI and report condition, contact Telco and report condition.

Dial Tone Detect Override

In the event that Telco dial tone exists, but the Communicator's dial tone detect circuit is not operating properly, the Communicator can be Factory Remote programmed to override the condition (until the System is replaced). To determine if this condition exists, extract the Communicator's diagnostic, either via the Poller or the optional On-Site Audio Verification. If a report is generated stating: "System failed, cannot detect dial tone, dial tone detect circuit failure... Please check System," contact TTI and report condition.

Voice Detect Override

In the event that the Communicator's voice detect circuit has been damaged through a severe electrical or phone line surge, the Communicator can be Factory Remote programmed to override the condition. If the handset is mechanically functioning properly and the mouthpiece is not transmitting, contact TTI and report condition.

Microprocessor Supervisory Circuit "Watchdog"

In the event of a severe phone line or electrical disturbance (surge/spike), entering the Communicator's circuitry, is to such an extent that is causes the system's processor to stop running; an on-board "watchdog" circuit will reset the System within seven (7) seconds from the moment of detection. This circuit constantly monitors the system processor's "heartbeat" and in the event, for any reason, it halts, the Communicator is automatically reset. Upon reset, the Communicator will initiate its "POST" (Power On Self-Test). During that POST, it will verify that the memory (RAM) is intact. (Phone numbers and System parameters are stored in RAM.) If the RAM test does not equal the appropriate "check-sum" (proper programming), it will be erased and rewritten with data stored in a backup location. This is performed on an individual memory address basis.