Dual display bonus for digital fibre-optic sensor

Edited by the Engineeringtalk editorial team Apr 24, 2002

Keyence reckons digital fibre-optic sensors have taken a giant leap forward with the introduction of its new FS-V20 series.

Keyence reckons digital fibre-optic sensors have taken a giant leap forward with the introduction of its new FS-V20 series.

As well as being the industry's first to incorporate a dual digital display monitor, the new series also includes a host of other innovations designed to improve both sensor and fibre cable performance.

The dual digital display monitor means that, unlike conventional sensors, the FS-V20 does not force users to choose between preset value and current value display.

As preset value changes can be made at the same time as monitoring the amount of light received, reliable system configuration is made much simpler.

Similarly, conventional, single-monitor sensors do not allow users to check amplifier mode status while making setting changes.

However, the dual display monitor gives users full access to amplifier status, allowing calibration of the sensor to be performed without stopping the machine or production line.

This makes set up simple, even for operators new to the product.

Keyence's own, in-house processor ensures that the amount of received light by the FS-V20 series is approximately four times that of conventional models, allowing it to sense reliably up to 3600mm with a through-beam type fibre.

This is important because it ensures stable detection, even in poor and deteriorating detection conditions.

The unit detects up to 10,000 targets per second using its industry-best response speed of 50us.

Conventional digital models typically have a response speed of 250us and perform a maximum of 2000 counts per second.

Using the high-resolution mode expands maximum incident level to 65,520 from the conventional 4095 for sensing close targets.

When long detecting distance, harsh environments and easy optical axis adjustments are called for, the FS V20's ultra high power mode is ideal.

Two other sensing modes are designed to solve problems such as the failure of sensitivity settings due to slow response, and received light saturation.

This is an important consideration as fluctuations or decreased light emissions over a long period may compromise high precision detection.

While these problems often cause conventional sensors to fail, the FS-V20 has two solutions.

First, Keyence uses a four-element LED, rather than the conventional three-element LED that loses brightness with extended usage.

Then there is the selectable auto-power control (S-APC) feature that maintains constant light emission by regulating current input to the light emission element.

For ease of use, the new series requires no extra wiring or man hours of work when amplifier expansion is needed.

Power is supplied through the connector on the side of each adjoining amplifier, where the same connector is used to lock each unit to the next.

Each sensor then saves two power supply wires that are normally needed by conventional sensors.

As a selectable power saving function, the digital display turns off if the sensor is not operated for 30 seconds.

At this time, power consumption will not exceed 480mW, even if a number of sensors are used in combination.

In another innovation, a metal strip on the back of the sensor becomes a heat sink when clipped to the DIN rail.

In combination with the FS-V20, Keyence has been offering a wide range of multi-core fibre cables designed to maintain signal resolution under conditions that would cause it to degrade in conventional fibres.

The Armoured ToughFlex, Super ToughFlex and ToughFlex ranges include both reflective- and thrubeam-type fibres designed to be more flexible than conventional single-core fibres.

Designed to resist entanglement and shock, they can bend without affecting optical attenuation.

Minimum bend radius varies from 0.5 to10mm.

The fibres themselves are connected to the sensor through tough elastomer ports that increase protection against bending, shock and dust ingress.

Together, Keyence's FS-V20 series and its new fibres offer industry an innovative solution to the ever-growing demand for improved sensor technology.

Cost savings are also likely because members of the FS-V20 series are very competitively priced and one model can often conduct the job of three or four conventional sensors.

(This was Engineeringtalk's Top Story on 23 April 2002).