What Is an Alarmed-Carrier PDS? ShortPDS FAQs
CNSSI No. 7003 addresses Protective Distribution Systems used to protect unencrypted national security information as it passes through areas of lesser classification or control. For an applicable Category 2 PDS, an alarmed carrier is one permitted protection method when routine visual inspection is impractical. ShortPDS adds continuous electronic tamper monitoring to short, point-to-point conduits, pipes, raceways and cable trays. The complete PDS design remains subject to review and approval by the responsible Authorizing Official and cognizant security authority.
What is an alarmed-carrier PDS?
It is a Protective Distribution System in which an approved alarm system continuously monitors the carrier, or the space around it, for attempted penetration. With ShortPDS, a copper sensor cable is installed along the outside of the carrier or threaded through it so mechanical activity associated with drilling, cutting, lifting or other tampering can produce an alarm.
Does CNSSI No. 7003 recognize alarmed carriers?
Yes. CNSSI No. 7003 identifies an alarmed carrier as one of the available Category 2 carrier methods. It requires the alarm system to detect attempted penetration, report faults, resist tampering, annunciate to a continuously staffed location and support the required security response.
ShortPDS is a component that can support such a design. Compliance and approval apply to the complete installation, not to the sensor alone. The department or agency Authorizing Official is responsible for approving, certifying and recertifying the PDS.
Does an alarmed carrier eliminate daily visual inspections?
For an approved alarmed carrier, CNSSI No. 7003 does not require the routine visual inspection schedule listed for non-alarmed carriers. It does not eliminate all inspection, testing or operating requirements. Each alarm zone must be functionally verified at the interval required for the classification of the information carried: monthly for Confidential, weekly for Secret, and daily for Top Secret or Sensitive Compartmented Information, unless the responsible authority imposes different or additional requirements.
The approved standard operating procedure must also address alarm response, investigation, maintenance, transmission shutdown and fault reporting.
Where is ShortPDS typically used?
Typical applications include short runs between secure rooms, from a SCIF or other Controlled Access Area to an IT or telecommunications room, through controlled or limited-access corridors, above accessible ceilings, and between approved areas in the same facility. The route and surrounding access conditions must match the approved PDS design.
What types of activity can ShortPDS detect?
ShortPDS is designed to detect vibration patterns associated with attempts to drill, cut, lift, open or otherwise penetrate the protected conduit, pipe, raceway or cable tray. Detection performance depends on proper mechanical coupling, installation, configuration and commissioning tests on the actual carrier.
How much can one ShortPDS processor monitor?
One processor can monitor up to four independent conduits or zones, each with up to 1,000 ft (300 m) of copper sensor cable. The maximum combined sensor length is 4,000 ft (1,200 m). Each zone has separate intrusion and line-monitoring outputs so the receiving system can identify which run generated the event.
How does ShortPDS reduce nuisance alarms?
The system combines vibration-frequency analysis, automatic live calibration and independently adjustable sensitivity. The processor provides 22 onboard sensitivity levels per zone and up to 500 levels through the configuration software. Final settings should be confirmed by testing representative tamper activity and normal background conditions on every zone.
Does ShortPDS require a server, software license or network connection?
No. ShortPDS operates as a standalone system and does not require a server, recurring software license or network connection for normal alarm operation. A local USB-C connection is available for detailed configuration, and optional RS-485 or IP communication may be specified when required by the project.
How does ShortPDS report alarms and faults?
The four-zone processor provides eight dry-contact relays, normally used as separate intrusion and line-monitoring outputs for each zone, plus dedicated tamper and power-outage relays. Contacts are rated at 1 A at 12 VDC. The relays can connect to a standard alarm panel or to a VMS, DVR, NVR, access-control or SCADA system with compatible alarm inputs.
Can ShortPDS be added to an existing conduit or cable tray?
Yes, in many projects. The sensor can be attached along the outside of a metal or plastic conduit, pipe, raceway or tray, or threaded through a suitable carrier. However, adding a sensor does not automatically make an existing route an approved PDS. The carrier, joints, pull boxes, terminations, access controls, monitoring location and response plan must all be reviewed against the applicable requirements and approved design.
Does the sensor touch or affect the protected network cables?
No. The ShortPDS sensor cable monitors mechanical activity on the carrier and does not connect electrically to the protected data cable. It therefore does not carry network traffic or alter the signal on the protected line.
Can an unencrypted PDS cross an Uncontrolled Access Area?
No. CNSSI No. 7003 states that a PDS carrying unencrypted national security information is not permitted in an Uncontrolled Access Area. A National Manager-approved encryption solution is required for that portion of the route. The Authorizing Official and cognizant Certified TEMPEST Technical Authority should be involved early in the design.
What should I use when a route is longer than 1,000 ft (300 m)?
FiberPDS is designed for long routes measured in kilometers or miles. A project can use ShortPDS for short in-building segments and FiberPDS for longer paths, provided the combined design and alarm response are documented and approved.
How do I plan a ShortPDS deployment?
Send RBtec a floor plan or route drawing showing the origin, destination, carrier type, run length, pull boxes, accessible sections and alarm-panel location. RBtec can recommend zones, sensor lengths and system components and provide product documentation for the PDS approval package. The PDS owner remains responsible for obtaining the required project approval.
Still have questions?
Contact RBtec at +1 (301) 760-4016 with your route drawing and carrier details. Our team can help develop the ShortPDS sensing layout and bill of materials for review by your security and accreditation authorities.