SST (Pakistan Educators Recruitment Tests) key terms

The overall layout of a system's devices, connections, and data paths, showing how components are grouped and how they interact to deliver the required function.

The central equipment location where signals from field devices are collected, processed, and often displayed or recorded; it usually houses controllers, power supplies, and network gear.

A defined group of devices treated as one unit for reporting or control, so an operator can quickly identify roughly where an event occurred rather than searching device by device.

A field device that carries its own unique identifier on the system's communication circuit, letting the controller report its exact location and status instead of only the shared circuit.

An off-normal indication that something needed for proper operation is degraded, such as a disconnected wire or low battery, warning of a condition that could stop the system working when needed.

A design in which loss of power or control leaves a device in its restricted state, so protection of the asset is maintained even when the system is down or de-energized.

A set of relay contacts that carries no voltage of its own; it simply opens or closes a circuit, so the connected equipment supplies whatever voltage and current it needs.

A structured walkthrough of the location before installation to record dimensions, existing conditions, obstacles, power and network availability, and any constraints that will shape the design.

The physical connection of a conductor to a terminal, connector, or device, made by the manufacturer's specified method so the joint is electrically sound and mechanically secure.

A table listing every cable run on a job, including its identifier, type, route, endpoints, and length, used to plan pulls, order material, and record what was installed.

A method of delivering both data and DC power to a device over the same Ethernet cable, limited by the switch port's power budget and the cable's current-carrying capacity.

A fixed network address assigned to a device by hand rather than leased automatically, so other equipment can always reach it at a known, predictable location on the network.

The embedded software that runs a device's processor and defines its features and behavior; it is updated to correct defects, close security gaps, or add capability.

Grounding provides a deliberate path to earth for fault and surge current, while bonding ties metal parts together so they stay at the same potential and cannot arc between each other.

A component that diverts or clamps brief high-voltage transients on power, signal, or network lines before those spikes reach and damage sensitive equipment downstream.

A recorded snapshot of normal readings and settings taken while the system is known to be working correctly, used later as the comparison point when something appears wrong.

Scheduled, planned servicing such as cleaning, tightening, testing, and replacing wear items, performed before failures occur in order to keep reliability high and extend equipment life.

A time-stamped record the system keeps of what happened and who did it, covering alarms, trouble conditions, logins, and configuration changes; it is primary evidence during an investigation.

An off-site monitoring facility that receives signals from customer systems, initiates dispatch, and notifies the responsible parties according to an agreed written procedure.

An alarm signal produced without a genuine hazard, caused by environment, installation practice, or user error, which wastes response resources and erodes confidence in the system.

A rechargeable battery that powers the system when the normal supply fails, sized to carry the load for a defined period and then keep the system running afterward.

The average time needed to restore a failed item to service, measured from the moment it stops working; a key measure of how responsive a maintenance organization is.

The documented process of bringing an installed system from mechanical completion to verified operation, through correct settings, checks, and functional tests before the owner accepts it.

A formal, often witnessed test demonstrating that the finished system meets the specification and contract requirements, typically triggering handover and release of final payment.

A procedure in which a technician moves through the coverage area and triggers each device in turn, confirming that every one reports to the panel with the correct identity.

A check for an unbroken conductive path using a meter or tester, performed with the circuit de-energized to confirm that wiring is intact and correctly connected end to end.

A handheld instrument that measures voltage, current, resistance, and often continuity, used to verify supply power, confirm wiring integrity, and isolate faults during troubleshooting.

A structured method for moving past the immediate symptom to find the underlying reason a failure occurred, so the corrective action prevents recurrence instead of merely restoring service.

The organization or official with legal authority to interpret and enforce the applicable codes for a given installation, whose approval is required before a system is accepted.

Evaluated and certified by a recognized independent testing laboratory as meeting a published safety standard; the listing mark shows the product was assessed for its intended use.

A safety procedure in which energy sources are isolated, locked, and tagged by the person doing the work so equipment cannot be re-energized while someone is servicing it.

The clothing and equipment worn to shield the body from workplace hazards, such as gloves, eye protection, and insulated tools, selected according to the task being performed.

The percentage of a conduit's internal cross-section occupied by the conductors inside it; codes cap this so cables can be pulled without damage and heat can dissipate.

Drawings updated to show the system exactly as it was installed, including field changes and deviations from the design, so future technicians can rely on them during service work.

A documented list of outstanding defects and incomplete items identified at inspection, with each item tracked to closure before the project is treated as finished.

A compiled reference for the owner containing equipment data, settings, maintenance tasks, and troubleshooting guidance needed to operate and care for the installed system.

A written authorization and record for a service task that identifies the site, the reported problem, the work performed, the parts used, and the time spent.

A contract term defining the service levels a provider must meet, such as response time and uptime, together with the remedies that apply when those targets are missed.

The formal transfer of a completed system to the owner or operator, including demonstration, operator training, and delivery of the records needed to run and maintain it.