opto-switches, how are they connected

Hello everyone

I am new to plc's and have been given a s7-200 plc to control a vertical gantry. It uses optical switches to alert the plc to stop the vertical motor once it passes the desired optical switch. there are 4 of them and each has a particular job for the gantry to do at the optical switch point, therefore the are turned on one at a time. I do not know how to connect them as each one has 4 pins 2 for the emitter and 2 that give an digital output when the light beam is cut. please help me understand how to wire it
thank you


sala

Hi,

You have not mentioned the make of optical switch but as it is 4pin most common pin configration is
Pin1= +24V
Pin2= NC output
Pin3= 0 V
Pin4= NO output

Arun said:

Hi,

You have not mentioned the make of optical switch but as it is 4pin most common pin configration is
Pin1= +24V
Pin2= NC output
Pin3= 0 V
Pin4= NO output

Click to expand...

It depends on what is the range of supply voltage you use, some is 220V-110V AC and the other is 24V-12V DC. But for sure the 2 pins is for supply then the other 1 is for your output, then the last pin is for NPN/PNP switching either light mode or dark mode.

Regards:

Sherwin

opto-switch

thank you for answering
the make is an RS 306-061. It is not found on the site again but in the spec sheet is found here:
(http://www.rs-components.hu/ds/232_2447.PDF). My concern is actually how to wire these opto-switched to the PLC input module itself(siemens s7-200 cpu=222, i/o module= em223). there is an application for limit switching on the sheet on page, can someone shead some light on this for me please
thank you

The document I viewed is an individual component. Not a sensor like we see in the industrial world. It is a optoisolator in a sence with a gap that the infraed led can be broken to the opposite phototrainsistor (NPN) on the other side. To simply hook this up to a PLC even if you did this correctly would burn up the part. The NPN trainsistor in your case has the collector pin 1 as positive and the emmiter pin 2 as the negative. There should be a load resistor between the emmiter (pin2) and ground so you do not burn up the part. This will make a positive voltage on pin 2 and the spec sheets say do not go above 30 ma. You would need to design an amplifer circuit. And I think that your Siemens PLC is sinking. So you need to Invert that output to go go your PLC. But my best advice would be to buy the right type of sensor and output that directly to the PLC. If not email me and maybe I can help you.

Opto sensor

If you look at figure 4 on page 2 of the part specification you attached, there is an example showing the supporting circuitry required to use this sensor. I would not recommend the use of anything this flimsy on a gantry crane though.

Try these links for some decent sensors
http://www.bannerengineering.com/
http://www.omronsensors.com/
http://www.keyence.com/
http://pewa.panasonic.com/acsd/