(Vision Sensing) The ratio of the focal length of a system to the diameter of the entrance pupil.

Tests and approves products for use in explosive areas. Abbreviated as FM.

(Machine Safety) A design or event in which a failure or fault within a system causes the hazardous machine motion or process to achieve a safe state. Commonly confused with "failsafe."

A description of a circuit or system that is guaranteed not to fail in the event of a malfunction so that the catastrophic loss of function is not possible.

(Machine Safety) An event in which a circuit or device ceases to perform its required function. See Fault.

(Machine Safety) A failure which delays or prevents a safety system from arresting dangerous machine motion, thereby increasing risk to personnel.

Refers to a change in a sensor's output, when there should be no change.

Any response time that is faster than 1 millisecond.

(Machine Safety) The state of an item (e.g. component, circuit, device or machine) characterized by its inability to perform a required function. A fault is often the result of a failure of the item itself, but may exist without prior failure. See Failure.

(Machine safety) The ability to minimize or eliminate known possible failures or faults through design, selection of components, or implementation of additional measures.

(Machine Safety) The ability of a system to function as it was designed even in the presence of faults or failures.

Federal Communications Commission. U.S. government agency mandated with interstate and international communications regulation including wire, cable, radio, TV and satellite.

(Vision Sensing) Used in vision applications to describe any characteristic descriptive of an image or a region in an image.

A ceramic, plastic or stainless steel part of a fiber optic termination that holds the end of the fiber and aligns it to the sensor of fiber mounting.

(Field Effect Transistor) Bilateral FETs are semiconductors used as the output switch of some sensing devices for their ability to switch either AC or DC, their low on-state voltage drop, and their low off-state leakage current. FETs are not tolerant of inrush current, typical, or inductive loads.

(Wireless) Frequency Hopping Spread Spectrum. A method for generating spread spectrum transmissions where the signal is switched between different frequency channels in a pseudorandom sequence known by both the transmitter and the receiver pair. FHSS is useful for sending small, redundant packets of data in a high interference environment.

A thin filament of glass or plastic consisting of a core (inner region) and a cladding (outer region) and a protective coating.

Transparent fibers of glass or plastic used for conducting and guiding light energy. Used in photoelectrics as "light pipes" to conduct sensing light into and out of a sensing area. Learn more about fiber optics here.

The area of response of an optical sensor.

The area of object space imaged at the focal plane of a camera.

A device placed over a light source or a sensor to select or reject specific frequencies of light.

(Machine Safety) Machine’s safety-related control system that interrupts the machine primary control element circuit when the output signal switching device goes to the OFF-state.

Security scheme designed to keep a computer network safe from unauthorized usage.

(Machine Safety)A way to configure a light screen system to ignore stationary objects (such as brackets or fixtures) that are always present at a specific location within the defined area. If a “fixed blanked” object is moved within or removed from the defined area, a Lockout condition results.

(Machine Safety) A simple and permanent type of machine guarding, used around the hazard as a barrier to prevent access or to contain a dangerous hazard.

Fixed-field sensors use two receivers and a comparator circuit to cancel sensing response whenever the intensity of the reflected light reaching the long-range receiver exceeds the intensity of the reflected light reaching the close-range receiver. As a result, any object lying beyond the sensor's fixed "cutoff point" can be reliably ignored. Here is a downloadable reference about sensing modes.

(Wireless) Proprietary power management scheme that enables a device to accept battery, 10-30Vdc, or solar power

(Machine Safety) See Reduced Resolution.

The emission by a material of light radiation at a longer wavelength, as a result of the absorption of some other radiation of shorter wavelengths. One example of this is when visible light is emitted as a result of the excitation of ultraviolet light.

A lamp producing light by exciting a phosphor with a plasma with the phosphor re-emitting the energy as light.

Bouncing or vibrating movement of a sensing target.

(Wireless) Frequency modulation. A type of modulation in which the data signal is “attached” to the carrier wave by varying the frequency of the carrier wave.

(Machine Safety) Abbreviation for Failure Mode and Effects Analysis, a testing procedure by which potential failure modes are analyzed to determine their results or effects on the system. Component failure modes that produce either no effect or a Lockout condition are permitted; failures which cause an unsafe condition (a failure to danger) are not. Banner safety products are extensively FMEA tested.

The distance from a lens' principal point to the corresponding focal point. Also referred to as the equivalent focal length and the effective focal length.

The point at which the lens focuses the image. The imager is located at the focal point.

(Vision Sensing) Acronym for Feature of Interest. The crucial visual information within the imaged scene that the customer is trying to detect for an inspection.

(Machine Safety) Relay contacts that are mechanically-linked, so that when the relay coil is energized or de-energized, all of the linked contacts move together. If one set of contacts in the relay becomes immobilized, no other contact of the same relay will be able to move. The function of forced-guided contacts is to enable the safety circuit to check the status of the relay. Forced-guided contacts are also known as “mechanically-linked contacts,” "positive-guided contacts," "captive contacts," "locked contacts," or "safety relays."

Acronym for Field of View. The area of object space imaged at the focal plane of a camera.

(Vision Sensing) A device interfaced with a camera storing in memory, on command, sampled video converted to digital signals.

The number of reccurrences of a periodic phenomenon in a unit of time. Electrical frequency is measured in Hertz (Hz).

(Measurement and Inspection) The maximum frequencies an analog sensor can track. All analog sensors have an inherent response time that limits their ability to measure periodic motions at high frequencies.

(Vision Sensing) An arrangement in which the object is illuminated and viewed from the same side.

(Machine Safety) Abbreviation for Final Switching Device. Component of a safety-related control system that interrupts the circuit to the machine primary control element when the output signal goes to the OFF-state.

(Measurement and Inspection) The full scale range of a sensor represents the maximum measuring range possible. If a manufacturer lists a performance specification in terms of “% of full scale.” The errors will not shrink with the calibrated measuring span, as they would if the manufacturer listed the spec in terms of “% of span.”

(Machine Safety) A method of machine drive arranged such that, once started, the machine can be stopped only when the full cycle is complete. Examples include positive key clutches and similar mechanisms.