Can the outputs of photoelectric sensors be connected in parallel?

Yes, the NPN or PNP outputs can be connected in parallel.

Can the Photoelectric Sensors be damaged in presence of a short-circuit of the NPN or PNP output?

No, thanks to the internal circuit that protects the output against overload.

Can the amplifiers of the TEN Fiber Optic series be used as contrast sensors?

Yes, using the TEN-2-x or TEN-5-x models, with double red or green emission and 5kHz switching frequency, preferably together with the OF-44 coaxial optic fibre and the AF3 or AF4 focussing lenses.

Is the laser emission of the SL5 Photoelectric series dangerous?

No, any eye or body exposure to the LASER emission of the SL5 photoelectric sensors is not dangerous, as the emission type is inside the limits foreseen for the class 1 complying with the EN60825-1 standard.

Does a photoelectric sensors with a lens defogging system exist?

Yes, the S30 Series presents versions with electrically heated protection glass and thus avoid fogging. These models are identified by the M letter at the end of their description, e.g.: S30-5-B8-2P-M.

Does a glass protection for the lenses of the M18 photoelectric sensors exist?

Yes, the MEK-proof accessory, composed of a metal o-ring and a circular glass lens which can be screwed on the optic side of the sensor housing.

What does the green LED in the universal sensors with basic optic functions indicate?

The green 'stability' LED indicates the received signal level and it facilitated sensor alignment; when alit it indicates that the signal is superior to 130% of the minimum value necessary for output switching.

Why is the TEST function in the through beam photoelectric sensors necessary and how is it activated?

The TEST function allow the user to effect a preventive and autodiagnostic control of the correct sensor functioning without placing the object to detect between the emitter and receiver. The emitter emission is deactivated each time the TEST+ input is connected to the positive power supply, or the TEST- input to the negative power supply, and thus the object's presence is simulated, provoked the receiver output switching.

Which precautions have to be taken when installing photoelectric sensors with the background suppression proximity function?

The sensor has to be mounted ensuring that the object to detect intersects at the same moment the emitter and receiver lens axes, and thus the longer side of the sensor's optic results to be perpendicular to the flow line of the object to detect.

What does 'category 2' and 'category 4' mean?

The safety category foresees the devices ability to detect a defect that can provoke a safety function loss during functioning. The category 2 foresees that the autodiagnostic function can be effected in 3 typical moments: at the first machinery start-up, at each device intervention and lastly when the user requests it externally by means of the TEST inputs. The category 4 foresees instead that the autodiagnostic function is continuously and automatically effected within the device's response time.

When does a 'category 2' or 'category 4' device has to be used?

The EN-954-1 standard has been created to aid machinery manufactures in selecting the safety level necessary for the different machinery types. The standard is based on 3 fundamental parameters: the damage gravity that can be provoked, the frequency it can occur and the duration to the risk exposure of the operator and the possibility to avoid the danger. The combination of the three parameters defines the necessary safety category: a category 4 safety device has to be used in presence of high damage gravity, high risk frequency and exposure and non-avoidability.

What is intended by body protection, hand or limb protection and finger protection?

These terms are commonly used to identify the Safety Light Curtains resolution type. A resolution with 1,2,3 or 4 variously spaced beams is necessary for body protection; a resolution between 20 and 40 mm is requested for hand or limb protection, while a 14 mm resolution is used for finger protection.

Which is the minimum beam distance to maintain in presence of a safety device installed for body protection?

The EN-999 standard suggests the correct positiooning of the safety device. In case of one single beam, the ground-beam height has to be 750mm. In case of two beams, the 1st has to be positioned at 400mm and the 2nd at 900mm. In case of three beams, the 1st at 300mm from the ground, the 2nd at 700mm and the 3rd at 1100mm. Lastly, in case of four beams, the 1st at 300mm, the 2nd at 600mm, the 3rd at 900mm and the 4th at 1200mm.

What is the MUTING function and its use?

The MUTING function has been introduced to solve the application need to temporally deactivate one or more beams of the safety device, enabling the material passage through the dangerous area. The MUTING is activated by means of the safety device inputs, typically guided by external photoelectric sensors; moreover the safety device has to be connected to the muting signalling lamp, that signals the muting activation and avoids the protection intervention. The MUTING foresees that all the inputs are activated in a well-determined temporal sequence that avoids accidental activation.

What is the OVERRIDE function and its use?

This function allows to force a machinery stop, due to material present in the dangerous area after the MUTING function. The OVERRIDE function allows the forced safety device activation even in presence of interrupted beams. The activation requests a precise procedure; the START and TEST inputs have to be contemporary activated during the initial autotest phase and kept pressed until all the material has left the dangerous area.

What are automatic and manual re-sets?

Automatic re-set is activated when the safety device intervening to stop the machine after beam interruption, automatically re-sets as soon as the object has been removed. Whereas in the manual re-set, the operator has to guide the START input of the device, using an external button.

Can the DS3 Light Grids measure objects with a 0.5 mm precision?

No, the objects can only be detected in the crossed-beam scanning, the measurement can be made only in the parallel beam mode.

What is the difference between the absolute and relative measurement in DS3 light grids?

The absolute measurement provides a voltage signal proportional to the last optic interrupted and can be useful, for example, with objects presenting holes or openings. The relative measurement provides a signal proportional to the number of optics interrupted, and so the object width.

What is the difference between the relative and absolute detection in DS3 light grids?

In the first mode the object can be detected in any position inside the measurement field. In the second mode, in one pre-established position. These modes can thus solve many different applications, ranging from presence and orientation control, object identification as well as guide control.

The S80L-Y Distance Sensor is sensitive to the colour of the object to detect?

The time of flight measurement reduces the colour effect, which is very important in triangulation sensors.

What is time of flight technology?

It is the new technology of the S80L-Y distance sensor. This system, differently from the previous triangulation technology, offers the possibility of having an equal precision on the entire measurement field, which can be very wide. This system detects light thanks to a electromagnetic undulatory signal instead of direct reflection or optic room geometry; the photon corpuscolar nature becomes secondary. In this manner the time necessary for the emitted light to hit the target and come back is measured directly.

How can the programming parameters be changed, for e.g. the PID values of the microprocessor-based Temperature Controllers?

The microprocessor-based temperature controllers present a basic configuration protected by a keyboard software block. The PROG key allows the user to enter into the programming and run through the entire menu, reaching the 3rd level, where the configuration can be unlocked with the UP/DOWN keys passing from the [LOC3] indication to the [FREE] indication. It is now necessary to repeat the programming menu changing the requested parameters. To exit the programming menu and confirm the changed the SET key has to be pressed. A careful reading of the operator manual is recommended.

When is the ON/OFF control action necessary instead of the PID action?

Due to the minor frequency of the actuator activation, the ON/OFF action is preferred in heating or cooling systems that use gas or liquids such as gas heaters or refrigerator compressors. The PID action is used only with the more rapid and precise actuators, such as electric resistances.

What is the PID action?

In simple terms, the PID (Proportional-Integral-Derivative) action is an output regulation modality that guarantees maximum rapidity and precision. The Proportional Action controls the output power according to the distance of the temperature measured by the set-point value; the Proportional Band indicates in how many C/F degrees (near to the set-point value) the output power passes from 100% to 0%. The Integral Action progressively increases or decreases the output power in presence of a residual (reset) error; the Integral Time indicates the seconds needed by the output to double or half its value. The Derivative Action varies the output value according to the temperature variation speed (rate) in order to avoid the transitory error due to the systems thermal inertia; the Derivative Time indicates the seconds necessary to bring the action back to zero. The PID action controls the output power periodically modulating the ON and OFF status and changing the ratio: the cycle time is expressed in seconds, the period in Ton+Toff.

What is the Autotuning function?

When the Autotuning function is activated, the regulator effects 3 regulation cycles with ON/OFF actions and measured the period and amplitude of the temperature variations; the most suitable PID parameters of the thermic system are set according to these parameters.

What is the digital filter for the measured temperature indicator?

The digital filter stabilised the display visualisation, making 10 successive measurement's average, even if the regulation acts on the non-filtered measurement.

What has occurred if the output is continuously ON but the temperature does not increase?

In presence of a thermocouple, it is necessary to check the absence of a short-circuit or connection polarity inversion. In presence of a resistance temperature detector, it is necessary to check, in the regulator configuration, if the correct sensor has been selected; [rtI] for integral scale or [rtd] for decimal scale (please refer to Operator Manual).