Serial Control

[Djbell]

Hi All

I have a SICK WL12-2P430 sensor, it has 4 wires.

Brown - Live
Blue - Ground
Black Input High
White Input Low

Voltage DC 10 - 30v

What I would like to do is connect this via my RS232 port and detect an input on the Black wire. My initial thoughts were connecting Brown to RTS, Blue to Ground and Black to RD. I havent tried this and I really dont know how I can get RTS to provide a constant 12v to the sensor. Is this possible without other circuitry?

Regards

Djbell

 

[rclarke250]

check here.

http://en.wikipedia.org/wiki/RS-232

Most likely you would need a buffer circuit built from a op-amp comparative circuit with an out put that the serial port would detect, along with the software that would than interpret the input changes.

 

[edfair]

Are you sure you want serial? From the description it sounds more like looking at bits on a parallel port with an external power supply and modifications to handle the voltage requirements.

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[Djbell]

Ok I am a little further on, I have an external 12v power supply to run the sensor. If I connect the normally open (Black wire) to either an input on the serial or parallel, would this be detected or is there more to the inputs on the these ports?

 

[edfair]

It could be detected by a parallel port. But 12 volts is out of range for a parallel port. It is looking for 0 or 5 with real world values of something like under 1 or over 3.

The conversion can be accomplished by an opto-isolator.

You would also need to tie the 0 volt reference line into the parallel port or you would be reading a floating voltage that wouldn't register as anything.

It has been a while but IIRC the parallel port (assuming PC based) has both 0 and +5 available as references. My experience was with Motorola 6821 and 48v stuff in a polling program and I had control of timing loops while you may not.



Ed Fair
Give the wrong symptoms, get the wrong solutions.