VMD202

Wiring Example: The VMD202 is typically wired as follows. Put red wire to positive power and black wire to negative power (GND) in the gate operator or other power source. Power required is 12-41 VDC or 8-29 VAC. Then take the brown wire (NO) and put it into exit or free exit on the gate operator. Lastly put the green wire (COM) into com or gnd on the gate operator. Leave white wire disconnected.

There are many possible causes for this problem.

Power Lines or Transformers: Make sure there are no underground or above ground power lines, or power transformers near the probe or lead-in cable since significant changes to the magnetic field around the probe can cause detections.

Electrical Noise: Make sure to connect the device to earth ground. There are two ways to earth ground this device depending on whether it is standalone or wired into the sensitivity remote.

1. Standalone Earth Ground: Make sure the VMD202 black wire has a Y splice with one end isolated to earth ground and the other end wired to negative power as specified in manual.
2. Sensitivity Remote Earth Ground: Make sure the earth ground input on the sensitivity remote is connected to an earth ground.

Overloaded Power Supply: Try connecting the VMD202 to an isolated power supply with no other equipment on it to make sure its power source is not overloaded.

High Sensitivity: There is an optional sensitivity adjustment remote (VMD202-R) for this device. The remote has two operator power inputs that should be wired to the operator power and two probe power inputs where the black and red VMD202 wires connect. The sensitivity remote will have a flashing green light indicating it is working. Reduce the sensitivity by turning the sensitivity dial counterclockwise one or two levels to see if this prevents the false triggers. Test to make sure the sensitivity is still high enough to trigger when driving over the probe.

There may be a problem with the VMD202 relay.

1. Make sure the VMD202 controller has power and 3 minutes have passed for the device to calibrate. Disconnect any relay output wires color white, green, and brown (NC, COM, and NO) going to your gate operator.
2. Set digital multimeter to check for continuity. On the VMD202 wires, connect one meter lead to green (COM) and the other meter lead to brown (NO).

3. The meter should read open (OL, INF) and should not beep yet. Move a metal tool over the probe. Verify the meter reads less than 10 ohms and now beeps. If the meter is still showing open and does not beep, then the relay is defective.

Incorrect Wiring: The VMD202 is typically wired as follows. Put red wire to positive power and black wire to negative power (GND) in the gate operator or other power source. Power required is 12-41 VDC or 8-29 VAC. Then take the brown wire (NO) and put it into exit or free exit on the gate operator. Lastly put the green wire (COM) into com or gnd on the gate operator. Leave white wire disconnected.

Power: Verify there is 12-41 VDC or 8-29 VAC coming from the power inputs that the red and black wire are going into. If using the blue sensitivity remote, make sure the green light is flashing and check power at probe+ and probe- inputs.

Vehicle Moving Slowly: The probe will activate based on the speed and size of the moving metal object. A car moving 5mph will be detected 12 feet away from the probe. Waving a metal tool such as a shovel over the probe can also be used to test if the probe is working.

Low sensitivity: Increase the sensitivity dial by turning it one or two notches clockwise. Make sure not to increase sensitivity too high or the device may be activated by objects outside of the desired detection range.