Dog Fences and Robotic Lawn Mowers working together

Dog fence and robotic lawn mower can they work together?

So you have a dog fence and want to buy a Robotic Lawn Mower? You’ve been online and worked out that the two products may well interfere with each other. You don’t want your dog fence to fail and equally, you don’t want grass up around your ears! You need to find a robotic mower that will work with your dog fence or vice versa?

Why do robotic mowers and dog fences interfere with each other?

Both dog fences and robotic lawn mowers use a buried wire that acts as an antenna and conducts a radio signal. An electromagnetic signal field is created around the cable. All but one dog fence systems use an AM radio frequency. This is the issue with installing both robotic mowers and dog fences next to each other. As with a magnet when you bring the same poles together they repel the signal. If no signal is being emitted one or other of the units will not work.

Are there any robotic mowers and dog fences that will work in harmony?

Yes, there is one brand of dog fence that will work with some robotic lawn mowers. The DogWatch brand which is sold by DogFence in the UK is the only system that will work in close proximity with a robotic lawnmower without interference. We have noted from experience that the cheaper brands of robotic mower tend to be more prone to interference than the Premium brands. Similarly, cheaper dog fences are highly susceptible to false activation from all sorts of household objects. If you are installing a robotic lawn mower and a dog fence the chances are you will have to keep the two miles apart in order for them both to be effective. With the DogWatch fence, nothing will interfere with the dog fence.

The DogWatch system uses a Digital FM signal on either 4 or 8 kHz. These frequencies are very low and the FM signal is much less prone to false activation. AM frequencies are very susceptible to noise. Notably, noise affects amplitude which is where information is stored with an AM signal (AM = Amplitude Modulation). With an FM signal (Frequency Modulation) the signal is transmitted through frequency modulation and not amplitude. Noise-based interference is a common issue for AM dog fences.

What happens when there is interference with the robotic mower and the dog fence?

With our DogFence the robotic mower will not cause any loss of signal or false activation to your dog’s fence collar. If in the event there was any interference it would be the mower that would be affected. In these cases, the robotic mower tries to read the dog fence signal and becomes confused (poor thing!).

Moving the boundary wire may help the situation. Ideally, we recommend placing the dog fence wire outside of the robotic lawn mower loop. Depending on which brand of mower you choose you may have to keep a gap between the dog fence and the robotic mower boundary wires. Our Dog Fences can be re-programmed by the owner to either frequency and in many cases, this eliminates any interference issues.

To date, we have had very good success with the following products when used in close proximity. Interestingly we have found that the larger capacity mowers are more prone to picking up interference than those covering a smaller area. We strongly recommend that you do not cross over the wires with either system.