Level or Displacement Sensors

[vangjer]

So i'm trying to find a touch-free sensor that will output digitally (hi or lo) so I can use a PLC to communicate with it. If sensor reads that the distance is greater than 9in, then it outputs high to the plc. What kind of sensor am I looking at? Displacement sensor? Most displacement sensors are in analog and i'm having trouble looking for one that is digital.

 

[dV8r]

Check this one out:

http://www.turck-usa.com/Products/Linear_Displacement_Transducers_(LDTs)/

 

[tygerdawg]

what is your resolution requirement? Perhaps you can use one of Banner Engineering's or Sick's ultrasonic sensors. Or if you need high precision, there are a variety (Keyence, OMRON, others) of laser displacement sensors available. Generally those will give analog signals, but most can output a discrete signal based on a setpoint.

TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering

http://www.bluetechnik.com

 

[macmet]

I've used OMRON proximity sensors that you might be able to set-up to work as you require. The range was field adjustable.

 

[itsmoked]

It doesn't sound like you should use a displacement sensor at all. You should just use proximity sensors as macmet suggests. The sensor will change state when your mechanism has reached it.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[PHovnanian]

If sensor reads that the distance is greater than 9in,

Distance to what? What are the environmental conditions?

There have been some good suggestions made but there may be some characteristics that rule out certain technologies.

In general terms, what you are looking for is a sensor and controller combination. The controller will condition the sensor's output, make the over/under setpoint decision and provide a switch contact for the PLC to use.

 

[vangjer]

Great suggestion, I'll take a look into prox sensors.

I found a controller that has 6 analog inputs and will probably be using it to make decisions off of the analog output sensor.

Thanks for the help.