> For the complete documentation index, see [llms.txt](https://help.security.gallagher.com/knowledge-hub/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.security.gallagher.com/knowledge-hub/products/cc-hardware/perimeter-solutions/perimeter-keypads.md). # Perimeter terminals Learn which Gallagher terminal controls a perimeter system, and what an operator can do from it. The **Gallagher T20 Terminal** is how an operator works with alarm zones and fence zones at the fence line. From a T20 you log on, arm and disarm zones, change fence modes, lock a fence out to work on it safely, and view and acknowledge alarms, without a Command Centre client in front of you. The terminal does not make access decisions. It sends information to the Gallagher controller and acts on information the controller sends back. {% hint style="info" %} F5x/F6x fence controllers show status on their own display, so a terminal is not needed for indication. A terminal is for operations: arming, lockout, voltages and alarm handling. {% endhint %} ### Which terminal | Part # | Product | Use | | ----------------- | -------------------------- | ------------------------------------------------------------------- | | C300463 | T20 Alarms Terminal, black | Alarm and fence zone management. Cannot read cards. | | C300464 | T20 Alarms Terminal, white | Alarm and fence zone management. Cannot read cards. | | C300450 / C300451 | T20 Terminal, MIFARE | Card reader, plus alarm and fence zone management. | | C300460 / C300461 | T20 Terminal, Multi Tech | Card reader with mobile credentials over BLE, plus zone management. | | C305860 / C305861 | T20 Terminal, Multi Tech | Card reader with mobile credentials over BLE, plus zone management. | The T20 works with any F Series fence controller — F3x, F4x, F5x, F6x — in network control. Fence zone management is supported from vHT4.0, Command Centre vEL7.40. ### Capacities and supply * A T20 Alarms Terminal can control up to **25** fence controllers, or **50** fence zones. * Supply voltage range **9–16 V DC** measured at the terminal's own terminals. Approximately **12 V DC** is recommended. * Operating current depends on the supply voltage at the terminal. {% hint style="warning" %} The Alarms Terminal variants work when the fence controller is in **Network Control** mode. They do not work with a controller in standalone mode. {% endhint %} ### What you can do from a terminal | Task | Page | | ----------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Log on with a user code, card, PIN or duress code | [Sign in to a perimeter terminal](/knowledge-hub/products/cc-hardware/perimeter-solutions/perimeter-keypads/configure/keypads-logging-on.md) | | Arm all or selected alarm zones | [Arm alarm zones](/knowledge-hub/products/cc-hardware/perimeter-solutions/perimeter-keypads/configure/keypads-arming.md) | | Disarm all or selected alarm zones | [Disarm alarm zones](/knowledge-hub/products/cc-hardware/perimeter-solutions/perimeter-keypads/configure/keypads-disarming.md) | | Lock a fence zone out for maintenance | [Lock out a fence zone](/knowledge-hub/products/cc-hardware/perimeter-solutions/perimeter-keypads/configure/keypads-locking-out-a-fence-zone.md) | | Switch a fence zone between high voltage and Low Feel | [Change fence zone voltage mode](/knowledge-hub/products/cc-hardware/perimeter-solutions/perimeter-keypads/configure/keypads-changing-the-hv-lf-mode-for-a.md) | | View fence, battery and earth voltages | [Monitor fence zone voltages](/knowledge-hub/products/cc-hardware/perimeter-solutions/perimeter-keypads/configure/keypads-monitoring-fence-zone-voltages.md) | | View current and seven-day controller temperature | [Monitor fence controller temperature](/knowledge-hub/products/cc-hardware/perimeter-solutions/perimeter-keypads/configure/keypads-monitoring-fence-controller-te.md) | | View fence zone states and status codes | [Monitor fence zone status](/knowledge-hub/products/cc-hardware/perimeter-solutions/perimeter-keypads/configure/keypads-monitoring-fence-zone-status.md) | | Override a scheduled fence zone state | [Override a scheduled fence zone state](/knowledge-hub/products/cc-hardware/perimeter-solutions/perimeter-keypads/configure/keypads-overriding-a-scheduled-fence-z.md) | | View alarm zones and input states | [View alarm zones and inputs](/knowledge-hub/products/cc-hardware/perimeter-solutions/perimeter-keypads/configure/keypads-viewing-alarms-zones-and-input.md) | | View and acknowledge alarms | [View and acknowledge alarms](/knowledge-hub/products/cc-hardware/perimeter-solutions/perimeter-keypads/configure/keypads-viewing-and-acknowledging-alar.md) | | View the System Summary | [View the System Summary](/knowledge-hub/products/cc-hardware/perimeter-solutions/perimeter-keypads/configure/keypads-viewing-the-system-summary.md) | | Test alarm inputs | [Test alarm inputs](/knowledge-hub/products/cc-hardware/perimeter-solutions/perimeter-keypads/configure/keypads-alarm-input-test-modes.md) | | Use a terminal as a reader keypad | [Use a terminal as a reader keypad](/knowledge-hub/products/cc-hardware/perimeter-solutions/perimeter-keypads/configure/keypads-remote-arming-terminal-as-a-ke.md) | Lockouts can only be started and cancelled from a terminal, not from a Command Centre workstation. *** 🔗 **Related** * [Energisers](/knowledge-hub/products/cc-hardware/perimeter-solutions/energisers.md). The fence controllers a terminal arms and monitors. * [Perimeter intrusion detection](/knowledge-hub/products/cc-hardware/perimeter-solutions/perimeter-intrusion-detection-pids.md). The sensors that raise the alarms a terminal shows. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. 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