proximity sensor with PLC

[fita]

Hello
i am new to PLCS please tell me can i connect output of proximity sensor to PLC.
I want to make a program that: A door open when a person is near the door and doesnt close until he crosses the door ( i dont want to use timer ). Please help me how can i do this .

 

[Mfleming]

Make sure you have the correct hardware by making sure the polarity of your input is the opposite of the common on the PLC card. Common of sensor to common, output of sensor to input on PLC. The sensor should come with installation instructions (Load = PLC input).

As for the programming this is as basic as it gets. Without a timer you just have the sensor triggering the door open/close. I don't know if you have a seperate output to close the door or if it returns off a spring, ect.

Unless this is for a practice to learn PLC operation, I don't understand why a PLC would be used. Why not use a simple relay instead?

Please try to include more information next time you post. List specifics on all hardware as in what type of output, PLC model, type of sensor used, ect.

IE: How do I connect a two wire proximity switch to a 1746-IB16 card and how can I use it to control a door using a spring return valve without a timer?

 

[ivo.maenen]

this should help you:

 

[fita]

Thanks

Thanks Mfleming i really appericiate ur reply.i just want to check working of PLC. Actually wat i require is how the pLC works
I am using VIPA control unit. i will try wat u just told

Thanks

 

[Mfleming]

Your welcome. Good luck learning plc's.

Your rung will look like this.

Proximity switch Door open
--I I------------------------( )---

And if you used a double valve add this rung as well.

Proximity switch Door Close
--I/I------------------------( )---

 

[Roy Matson]

Be aware that the leakage current of many proximity detectors is more than the turn off current of a PLC input, In other words the input will turn on but not off again. This applies in particular to the 120 VAC 2 wire variety. Check the specs of both carefully.
Roy

 

[Pego]

Be aware that the leakage current of many proximity detectors is more than the turn off current of a PLC input, In other words the input will turn on but not off again. This applies in particular to the 120 VAC 2 wire variety. Check the specs of both carefully.
Roy

This ONLY applies to 2 wire(so only AC) sensors.

 

[ivo.maenen]

This ONLY applies to 2 wire(so only AC) sensors.

http://www.am.pepperl-fuchs.com/products/productsubfamily.jsp?productsubfamily_id=1583

Is it not that 2-wire can also be 'DC'?

 

[fita]

using LOGO

Please tell me another thing 1st i will tell u current senario

There is a water fall (GATE) which should stop when i come near it and when i pass it should start water again , i cannot afford to use a timer as the worker might stop in middle of the door

Is it possible for me to implement this using Siemens LOGO.

How can i hold the value of sensor to a high value that unless i cross the door ( or other sensor ) it doesnt let the water to FLOW????
it sholud work both ways that is it sld provide two way entry
please help

 

[milldrone]

Please tell me another thing 1st i will tell u current senario

No, tell us everything first, then we can help.

There is a water fall (GATE) which should stop when i come near it and when i pass it should start water again , i cannot afford to use a timer as the worker might stop in middle of the door

I cannot determine if there is a language problem here, or if the requirements are changing or what. In the original post you mentioned.

I want to make a program that: A door open when a person is near the door and doesnt close until he crosses the door ( i dont want to use timer ). Please help me how can i do this .

This implies that you want the door to open before a human gets to the door. Then you do not want the door to close until he has passed.

Typically this would be a job for a pair of photo eyes not a prox.

Is it possible for me to implement this using Siemens LOGO.

In this post you said

I am using VIPA control unit.

Changing requirements?

Now back to

Is it possible for me to implement this using Siemens LOGO.

If this is a safety thing, this cannot be done here in the states.

it sholud work both ways that is it sld provide two way entry
please help

More changing requirements?

Assuming that I'm interpreting your last post is the correct set of requirements you will need four through beam photo eye setups (4 receivers and 4 emitters) and 4 inputs to make this work.

You will need to place 2 setups on each side of the waterfall.

The need for 2 on each side is because we need to sense what direction the human is traveling.

This is assuming I have interpreted your last post correctly. It is very possible I have failed in this regard.

 

[fita]

Sorry SIR

More changing requirements?

Assuming that I'm interpreting your last post is the correct set of requirements you will need four through beam photo eye setups (4 receivers and 4 emitters) and 4 inputs to make this work.

You will need to place 2 setups on each side of the waterfall.

The need for 2 on each side is because we need to sense what direction the human is traveling.

This is assuming I have interpreted your last post correctly. It is very possible I have failed in this regard.[/quote]


I am REALLY SORRY that u encountered so many problems regarding my posts please accept my apologies, you are correct regarding my final post

now please guide me how can i install them to check in which direction is the human travelling

 

[milldrone]

now please guide me how can i install them to check in which direction is the human travelling

Ok, place the through beam pairs at a height above the elbows and below the shoulders of most people . The reason for this is to try to eliminate the most amount of false triggers.


When photo eye a's beam is broken and photo eye b's beam just becomes broken set a bit, or seal a bit for one direction. Unseal it when c is broken and d just becomes broken.

Reverse for the other direction