Home' RTCA Documents for Review : DO-230H FRAC Contents 116
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As a person requesting access completes the process of presenting the required credential (i.e., a card) and
the subsequent access decision is access granted, the PACS generates two signals. One signal is to release
the barrier (unlock the door locking mechanism). The second signal is to ignore (mask) the change of state
that occurs in the door position switch as the door is opened and closed. This allows the door to be opened
without a door- forced open alarm being generated and sent to the SOC.
As the access procedure is completed, the person who requested access enters the secured area and as the
door closes the door position switch is once again returned to the “secure” state. This describes a completed
access transaction as envisioned for an authorized entry. In this case, there may not be any requirement to
capture and log anything other than the access transaction with location, date, time and person who was
Portal Forced Open
An adversary is exercising force to open the door. In this case, the PACS did not grant access and the door
position switch is not masked. In this example, the local PACS controller generates an internal “Door
Forced Open” alarm message which is sent to the PACS Server and may be forwarded to the SOC. This
message includes the date and time, type of violation door- forced- open and location of the breach.
System responses may vary, however it is common to include local annunciation, graphic display and
specific instructions to the operator and response force. In addition, many systems are capable of sending
instructions to specific video controller(s) to initiate video display for assessment purposes.
In this case, a predetermined event at a specific access location initiated a series of system events in several
subsystems integrated to the PACS or in some cases these functions may be native within the PACS
Portal Open Too Long
Another example covers a similar door. However, in this case, the access transaction is completed the
authorized person enter the secured area; but the door does not close properly. This may be due to a
malicious act of an adversary, or simply a miss-adjustment or mechanical malfunction. In addition,
variations of air pressure between the areas separated by the door is a common cause a door that
intermittently prevents the door from properly closing after an otherwise normal access event. In this use
case, at the same location, the different event generates a different signal, a door- open-too-long alarm. This
may be treated differently than the previously described forced open alarm. To accommodate variable entry
processes, different access control points may allow the door to remain open different amounts of time. An
example is a boarding gate, where cabin crews and staff members may only require the door to be open a
few seconds. However, during the passenger boarding process, the PACS may be programmed to allow the
same door to remain open for a longer period of time without generating a door-open-too-long alarm.
Attempts to tamper with a sensor or reader may be an indication an intruder is deliberately making an
attempt to circumvent a portion of the system to surreptitiously gain access to an area without the system
triggering an alarm message or generating an access log, or covertly enter an area where a person is not
authorized. Tamper alarm events may be programmed to be prioritized over other alarm messages such that
they are processed and annunciated before other lower-priority alarms are displayed.
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