Gates, barriers, and vehicle access

Gates and barriers involve moving machinery. Access software can request passage, while the approved local controller and safety functions govern movement.

Overview#

Powered gates and barriers are machinery. Access control may request passage, but the approved gate controller and safety functions decide whether and how movement occurs. Never treat a generic relay, PACS grant, ANPR match, or API success as motion authority or proof of safe passage.

Authority chain#

credential/plate/intercom/operator observation
 -> PACS or approved access-policy decision
 -> constrained open-cycle request
 -> gate controller evaluates mode, interlocks, and safety devices
 -> controlled movement
 -> position/presence/safety telemetry
 -> passage event and audit

Emergency stop, manual release, fire/emergency interaction, safety edges, presence detection, guarding, limits, drive control, and restart behaviour belong to the assessed machinery design. Integration must not bypass them.

Separate states#

Model at least:

• access request, decision, reason, credential/vehicle context, and expiry;
• controller mode: automatic, manual, service, emergency, locked out, or unknown;
• requested cycle versus accepted/rejected command;
• physical position: open, closed, intermediate, moving, unknown, and sensor disagreement;
• safety device active/fault, obstruction/presence, emergency stop, and interlock state;
• vehicle approach, authorised passage, tailgate/second passage, reverse, and abandoned transit where observed;
• power, network, controller, drive, communications, and clock fault;
• forced/manual movement, held open/forced open, and restoration.

Don't derive position solely from elapsed time after a command. Where several sensors disagree, report disagreement rather than selecting a convenient state.

Vehicle authorisation#

Credentials, ANPR/LPR, mobile credentials, ticketing, intercom release, schedule, occupancy/capacity, and operator action can contribute to policy. A plate alone isn't a person or entitlement. Define fallback for unreadable plates, lost connectivity, stale allowlists, multiple vehicles, trailers, motorcycles, visitors, and emergency response without weakening safety control.

Antipassback and occupancy estimates can be wrong after tailgating, manual operation, sensor failure, or offline use. They aren't safety rated presence systems or evacuation truth.

Machinery and life safety boundary#

Risk assessment must cover people, vehicles, cyclists, animals, crushing/shearing/drawing in/impact hazards, trapping areas, public access, foreseeable misuse, environment, power loss/return, manual operation, maintenance, and unexpected startup. Use the applicable local gate/door product and installation standards and competent authorised practitioners.

ISO 12100:2010 provides general machinery risk assessment and risk reduction principles; ISO marks it as expected to be replaced, so check status before use. ISO 14118:2017 addresses prevention of unexpected machinery startup. Neither substitutes for the applicable gate specific and local requirements.

Security and integration#

• Use a semantic, bounded passage request rather than unrestricted relay/register access.
• Separate PACS, gate maintenance, safety controller, intercom, and monitoring identities and privileges.
• Protect remote control and mobile clients with strong identity, constrained site/device scope, confirmation, and audit.
• Segment OT control from general user and cloud networks according to assessed dependencies.
• Validate command authentication, replay/duplicate behaviour, queueing, timeout, failover, and recovery.
• Expose stale telemetry and lost safety/controller communication prominently.
• Prevent automated cross domain rules from cycling a gate on an unverified alarm or analytics event.

Acceptance boundary#

Security integration evidence includes identity, policy, command scope, state correlation, failure visibility, and audit. Machinery safety validation, force/movement testing, emergency coordination, and live commissioning require the approved local process, competent specialists, manufacturer instructions, and applicable normative requirements.

See ANPR and LPR systems, Offline operation and antipassback, and BMS and SCADA integration.

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