Different sensor connection types
Electronic sensors require connection in order to receive their power and transmit their output. A connection diagram, included on the sensor’s datasheet and often printed on the device if room allows, labels each available connection point.
When designing FOUNDATION™ fieldbus or PROFIBUS PA networks, it is extremely important to make sure that the devices on those networks have enough power to start up properly and operate normally.
The fieldbus physical layer specification IEC 61158-1 defines the min/max voltage levels for FOUNDATION fieldbus and PROFIBUS PA. The minimum voltage required for any fieldbus device is 9 V and the maximum voltage allowed on a fieldbus network is 32 V.
To calculate the voltage drop along a fieldbus cable, you must know the number of connected instruments and their current consumption, as well as the resistance of the cable, cable length, and power supply voltage. Typical fieldbus devices consume 15 mA to 20 mA. The exact number can be found on instrument data sheets. A standard “type A” fieldbus cable has a typical resistance of 44 Ohm/Km and a typical fieldbus power supply supplies 30 V.
Knowing the total current draw, supply voltage, cable resistance, and cable distance of a segment, and applying Ohm’s law, allows you to deliver maximum distance and/or voltage drop at a certain distance.
To simplify these calculations, companies like Pepperl+Fuchs have created free-of-charge segment design tools like Segment Checker.
For companies who develop and manufacture large mobile equipment vehicles, sensors are a vital part of the control package for feedback to the processor. These sensors directly inform the processor of the status and position of the various processes throughout the vehicle. They must perform flawlessly for the vehicle to complete the function for which it was manufactured.
Choosing the correct industrial encoder is easy when you know the answers!
There are many reasons why you may need a rotary encoder, but what questions should you ask to determine which one is the most appropriate? Here are seven questions that can help you make the best decision: