Author Topic: Proximity sensors are too sensitive. What can I do?  (Read 2798 times)

Gallen66

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Proximity sensors are too sensitive. What can I do?
« on: July 02, 2018, 06:06:08 PM »
I have set up a CNC Router with a PMDX-126  BOB and ESS motion controller. I am trying to connect NPN-normally-closed (6v-30v) inductive proximity sensors as limit switches on connectors J11 & J12. I have them wired to pins 11, 12, 13 & 15 powered by the 12v ports on J11 & 12. I had to add resistors due to the “current leaking” from the NPNs’ signal wires to the corresponding +5v ports for each connector. That allowed me wire them up and successfully run the machine without tripping the limit switches so long as they were not close to the motors; however, when I went to mount the switches they went off as soon as they were anywhere near the motors. Is there any way to modify or adjust that? Does that have to do with “noise” from the motor or the sensitivity of the sensors or both or neither? Also I noticed that when they are activated, they don’t stop the machine, they just kept me from entering another command.

Steve Stallings

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Re: Proximity sensors are too sensitive. What can I do?
« Reply #1 on: July 08, 2018, 01:54:32 PM »
This may be magnetic interference from the motors. How close is close? I would
expect that 6" of separation should be OK.

Do the sensors have built in indicators? If so and if they light, then the issues
is with the sensor. It may be that your sensors will perform better with an external
24 volt power source.

Steve Stallings
www.PMDX.com