- TermDescription
- Conductor
Material with the ability to carry electric current. The term is also used for an electric wire.
- Conduit
A tube or trough for protecting wires and cables. It may be a solid or flexible tube in which insulated electrical wires are run.
- Connector
Generally, any device used to provide rapid connect/disconnect service for electrical cable and wire terminations.
- Contacts
Electrically conductive points used to make or break an electrical circuit mechanically.
- Credential
A credential is a physical/tangible object, a piece of knowledge, or a facet of a person's physical being, that enables an individual access to a given physical facility or computer-based information system. Typically, credentials can be something you know (such as number or PIN), something you have (such as an access badge), something you are (such as a biometric feature) or some combination of these items. The typical credential is an access card, key fob, or other key.
- Current
The flow of electrons through an electrical conductor. Current is measured in amperes.
- Daughterboard
A small PCB that when connected to an RTU converts from one communication protocol to another to allow the rtu to communicate with the host.
- De-energize
To remove power.
- Direct Current (DC)
Electrical current that travels only in one direction and has negative and positive polarity. It may or may not have an AC ripple component. DC sources that are unfiltered should be referred to as full-wave or half-wave rectified circuits.
- DNS
DNS is an abbreviation for Domain Name System, a system for naming computers and network services that is organized into a hierarchy of domains. DNS naming is used in TCP/IP networks, such as the Internet, to locate computers and services through user-friendly names. When a user enters a DNS name in an application, DNS services can resolve the name to other information associated with the name, such as an IP address.
- DOLT
Door Open Too Long: A door has been in the open state longer than the programmed maximum time allowed. This is one of the most common alarms in a system. A DPS (door position switch) is used to determine if the door is opened or closed.
- Door Forced
A door that has been entered without using the proper method of entry. This usually is determined by the change of the DPS state without a relay or valid card read at the door or portal being monitored for activity.
- Double pole, double throw, (DPDT)
A term used to describe a switch or relay output contact form (2form C) in which two separate switches operating simultaneously, each with a separate normal closed contract and a common connection. This form is used to make and break two separate circuits.
- DPS
Door Position Switch: A switch used to determine the position of a door. They usually are a magnetic reed switch which are triggered by a magnet installed in the top of a door. When the door lines up with the switch in the closed position the switch provides a dry contact signal back to the system.
- Dry contract
Metallic points making (closing) or breaking (opening) a circuit. The switch circuit must have its own source of power and is merely routed through the dry contacts.
- Earth Ground
The portion of a circuit that is connected to a buried metallic object such as a grounding rod or water pipe.
- Egress
Passage through an opening in the exit direction, especially passage that leads out of a structure.
- Electric Strike
A door unlocking device that is installed in the door jamb and that works in conjunction with a mechanical lock or latch mechanism.
- Electrified Lock
A mechanical locking device that has been modified to allow an electric circuit to lock or unlock it.
- Electromagnetic Lock (Magnetic Lock, Mag Lock)
A device that locks/unlocks an opening without moving parts, using pure electro-magnetic attraction.