M12 Sensor connector FE-pin

[xzen]

M12 sensor plugs are widely used. I'm about making my own CAD symbols for sensor connections, and I'm not sure about including pin #5, which is present only on some field equipment (Siemens). I myself have never cared about functional earth (FE). Neither have I observed any use of it. Any experience out there?

 

[bb76]

There are products that use pin 5 out there. We use a Sick DT50 laser sensor which has pin 5 as a multifunctional input to allow set up operations to be done remotely.

 

[JesperMP]

If there are 5 pins in the connector you should include them in the diagram, no matter if it is connected to a wire or not.
I am using M12 sensors and connectors that use all 5 pins. The function of pin 5 is not fixed to functional earth. It depends on the sensor.

 

[xzen]

Thanks guys! I'm familiar with both the Sick DT50 laser and other equipment that use pin #5. My question was really about the functional earth in particular. I guess it could be used for cable shielding. But then again: I have never seen anyone use it. I was just curious if anyone ever needed to use shielded sensor cables. I have experience with high speed sensors (kHz range), but never used anything but normal unshielded sensor cables.

 

[JesperMP]

Generally, analog signal cables are most often shielded.

 

[arpus4KM]

M12 sensor plugs are widely used. I'm about making my own CAD symbols for sensor connections, and I'm not sure about including pin #5, which is present only on some field equipment (Siemens). I myself have never cared about functional earth (FE). Neither have I observed any use of it. Any experience out there?

include it.

some sensors have the "gray" wire number 5 for enable or programming power.

ran into a sensor recently that would not work in my turck test unit because the #5 wire needed 24v to be active for the internal laser to work


as far as shielding or earthing.... if someone smarter than me says it needs it to be connected, then I'll generally just connect it and worry about finding out why later. some are required to be shielded, others aren't I guess.

 

[Jim3846]

That pin 5 i have seen in the field that its used as a pin guide with the tab. 1st to connect last to reconnect. So i know its used in the connector. Some devices are sensitive to noise and probably used to bleed of static electrical problems. I remember before one of the other pins was the pin guide and the electricians seemed to destroy those connectors, painful memory.