Extending RS-485 Gate Control Across Property Lines—Without Replacing What Works

When Growth Runs Into a Public Road

When a self-storage facility in the Southeast acquired a property across the street, the plan was simple: add a gate, connect it to the existing access control system, and keep growing.

The problem was the road in between. 

"I couldn't run a wire across the street," the owner said. "So I had to find another way to get there."

A Business Built Around What Works

The facility runs lean. As a one-person operation managing everything from tenant relations to maintenance to bookkeeping, the owner has developed a strong preference for tools that don't require constant attention.

The existing gate access system embodied that principle. Built on a legacy controller with RS-485 keypads at each gate, it had handled tenant access reliably for years. When modern access control systems began migrating to cellular connectivity with monthly subscription fees, the decision to stay with the existing RS-485 setup came down to simple math.

"All the modern gate control access systems are running on cellular now, and they're charging recurring fees," the owner said. "I can't justify paying those fees year-round."

The RS-485 network worked. It just needed to cross the street.

The Connectivity Gap

The solution came together using two technologies in tandem: LigoWave wireless bridge antennas to create a point-to-point wireless Ethernet link across the road, and Grid Connect's NET485 serial device server to convert RS-485 to Ethernet on each end of that link.

The topology is straightforward. On the main property, the RS-485 bus from the existing gate controller feeds into a NET485 configured in serial tunnel mode, which converts the signal to Ethernet. A LigoWave antenna then transmits that signal wirelessly across the street. On the far side, a second antenna receives it, feeds it into another NET485, and converts it back to RS-485—where the remote keypads connect exactly as if they were on the same wire.

"That's all I'm doing," the owner said. "I just needed to bridge a gap in the RS-485 network."

Getting the First Crossing Online

Getting the initial NET485 pair up and running took some trial and error. Establishing the host-client connection wasn't immediate, and the path forward wasn't obvious. The breakthrough came from the command line: running a ping to locate the device on the network was enough to wake it up and lock in communication.

"I couldn't get it to link up," the owner said. "I pulled up the command window, ran ping to see if I could find it on the network—and bam! It started working."

After that first connection, the devices have not needed attention.

"Once they start running, I love them. They're perfect."

Set It, and Leave It Alone

With the first crossing proven, expanding became straightforward. When a second parcel across the street became available, the facility added another NET485 pair and another gate—same architecture, same approach.

Today, four NET485 units run across the facility's properties. All of them have been operating without incident since installation.

"What I love about the product—you get it up and running and you don't have to touch it," the owner said. "It just sits there and works. It's great."

For a one-person operation, that reliability isn't a nice-to-have. It's a requirement.

RS-485 continues to serve as the backbone of the gate control system. As the business grows, the same proven approach—NET485 in serial tunnel mode, bridged over wireless Ethernet—offers a scalable, cost-effective way to extend the network wherever the next property might be.

"I don't know what I'd do without this product."

Grid Connect's NET485 provides RS-485 to Ethernet serial tunneling for applications where legacy serial networks need to bridge physical gaps or connect to IP-based infrastructure. The newer GRID485-ST offers updated hardware and software for the same serial tunneling use case.