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APeX common problems and solutions

Updated: Dec 8, 2023

The APeX control board was developed by Linear (now Nortek) back in 2008, at the time it was one of the most advanced gate operator control boards available. Almost 12 years later, the APeX board is still formidable in its capabilities for automatic gate controls. Over the years many dealers have found persistent issues with this board, quirks, if you will, that dealers understand and know how to manage. We will go over one of the most common with these automatic electric gate openers and troubleshoot APeX gate controller solutions can be had in the field or what Rotary Gate Systems has done to mitigate it before shipping.


Random EN 12 errors-

The EN 12 error code is commonly associated with a bad motor. While this is sometimes true, most often we see this error in other cases. EN 12 presents when any part of the system having to do with DC power has an issue, or when there is a problem with the DC motor board that attaches to the APeX control.

On residential systems, check battery voltages first. Any voltage on the batteries below 22VDC will cause odd problems, including EN12. If your batteries are showing 24 volts or above while idle, be sure to check them again under a load (while the motor(s) are running). Finally, disconnect the batteries from the APeX control and test again. Disconnecting the batteries from the controller eliminates the charging circuit as a variable, you may show stray voltage up to 27VDC while connected since this is the charging voltage.

On all systems, check power draw on the "ACCY PWR" terminals on the top left of the board. While this output is rated at 1A power available, many times we have issues when drawing more than .5A, or 500mA. Over drawing current from the accessory power terminals causes EN 12 issues.

Check the connection point on your DC motor board. This board can be found under the blue cover on the APeX control. Loose connections on the pins can cause communication issues resulting in any number of errors, including EN 12 and EN 11. Check on the left side of the motor board, directly under the "M2" terminal for a small nylon screw. This simple standoff and screw holding the motor board stable will solve more than 50% of the random EN 12 errors seen in the field, and was added by Rotary Gate Systems in 2015. If your control board is lacking this screw and matching standoff underneath the motor board, you will be doing yourself and your customer a favor by installing one. Contact Rotary Gate Systems for information on size, thread pitch, and benefits.

Finally, if you've checked all of these and still have EN 12 showing, even after resetting the system, follow the APeX gate controller troubleshooting instructions below:

Shut off power to the system.

Disconnect the motor wires from the white terminal strip on the lower right side of the back plate. (This is the terminal strip where all of your main connections come in, ie. power, motor, brake, and limit switches).

Find the "aux relay" terminal on the bottom of the APeX board.

Connect the two purple wires into the same terminal, it doesn't matter which one.

Disconnect your batteries from the system.

Turn power back on to the system.

Touch motor wires to the battery terminals. (Reversing polarity will only cause the motor to run in the opposite direction, no damage will occur).

Run operator in both directions, checking full travel of the gate. During this troubleshooting step limit switches will not stop the gate. Care must be taken to not damage the gate or other hardware while running the gate from the batteries.

This will test the motor for any issues not related to the electronics, if the motor does not run, call tech support for further instructions on troubleshooting these automatic electric gate openers.

Shane Jones

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What about a "FO" display with "open limit/brake delay and reverse/delay set" illuminated?

Shane Jones
Shane Jones
Jun 23, 2022
Replying to

"FO" and the "open limit/brake delay" are just indicators that the gate is fully open and on the open limit switch. "Reverse/delay set" is a reverse input, usually from a photo eye, safety edge, or safety loop. Make sure all safety devices are cleared and that the reverse LED goes out. If you cannot get it to clear, call an experienced gate operator technician to diagnose.


Shane, this is cool how you talk about the history of the apex control board. Don't forget to include pictures/video.

Thanks for the demo at Southwest Automated Dallas!

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