Greetings Soft Fan logo,

I have connected 2 balluff photoelectric sensors to detect 2 objects Input Object and Output Object. I want to make an error message appear when the cables are disconnected and an error message appear, the cables are disconnected. Can you help me please

What type of signal is it?

With unobstructed fluoroscopy, is it a 1-signal (light-switching)?

Or with interrupted fluoroscopy, is it a 1-signal (dark-switching)?

The signal is With unobstructed fluoroscopy, is it a 1-signal (light-switching)

And I want the message to appear on my LCD screen when the sensor cable or the sensor is not working.

You can only monitor a digital signal over time.

For example, with a light-switching photoelectric barrier, there's a switch-off delay. The switch-off delay then has a time value of 10 seconds, for example. If the beam is interrupted for longer than 10 seconds, the switch-off delay time can expire, and an error occurs.

Hello duma_calin145,

If the light barriers have a changeover contact as a switching contact, you can monitor the cable connection. Both outputs of a light barrier changeover switch can never have a 0-0 or 1-1 signal as a continuous signal. You evaluate the signal states using an XOR .If these states occur, there is an open circuit or short circuit.

However, to test the function of the light barrier itself, you need a second one.Both then monitor each other.

Regards, Ella_68

(translated by Google)

Dear Ella_68,

Thank you for your support. I made the program like this according to your model. I was unable to do the following: 1. When the cable is connected, I get an error on the LCD something like '''Cable or sensor not connected error' Do you think you could help me? 

Regards duma_calin145

Hello duma_calin145,

I think you misunderstood something. My example is only intended for monitoring the sensor cable. This monitors the signal change between the two signal lines (see image).

If you insert something in between, as in your program, you also change the monitoring requirements.

Since every sensor or switch has a point in the switching phase where the signal is 0-0 or, rarely, 1-1, I have provided a timer to bridge this time.This time is very short, and the module should be dimensioned to precisely suppress this error message.

Regards, Ella_68

(translated by Google)

Dear Ella 68,

Is more clear for my, thank you for your support and explication>

Redards duma_calin145