D20 Setup, Walkthrough, and Troubleshooting

Topics included in this article:

• Overview
• Prerequisites
• Compatible Devices
• Setup and Registration
  • Battery Requirements
  • Battery Life
  • Battery Installation
  • Registration
• Bluetooth
  • BLE Range
  • BLE Signal Strength
  • D20 Sensing Range
• Hardware Installation
  • Mounting Positions
  • Roll-Up Door Setup
  • Coiling Door Setup (3rd Party)
• Unregistering
• Troubleshooting
  • LED Indicators
  • Troubleshooting Steps
• Helpful Links
• Contact Support or Sales

Overview

The Rhombus D20 creates safer spaces with real-time entry point monitoring. The D20 sends timely alerts when access points are left open and connects to the nearest BLE-enabled Rhombus device to provide real-time sensor data with synchronized video evidence to ensure proper building security.

Prerequisites

Before registering a D20, you must to be signed into the Rhombus mobile app (Android or iOS), and in range of a BLE-enabled device that is registered to your Rhombus Console.

Compatible Devices

Before registering a Rhombus sensor, you must have a Rhombus device that supports the Rhombus Sensor Network. Confirm compatibility by visiting the device specs page on rhombus.com.

Below is a list of compatible BLE gateway devices:

• R120
• R2
• R170
• R200
• R230
• R360S
• R410
• R520
• R540
• R545
• R600
• A100
• DR40*
• E50

Note: Although the DR40 supports BLE, it is not designed to serve as a dedicated BLE gateway. Since BLE resources are shared with badge-in functionality, connectivity to BLE devices may be inconsistent.

Setup and Registration

Battery Requirements

The D20 uses 1x ER14505 AA Lithium Battery, which should measure a nominal 3.6v.

Note: ER14505 batteries are exactly the same size and shape as traditional AA batteries, but they have a different voltage. DO NOT install normal (1.5v) AA batteries into the D20; ensure that ER14505 batteries are used.

Battery Life

Expected Battery Life: Up to 8 years with typical medium-heavy use.

Battery Installation

1. Remove the battery cover located on the back of the D20.

2. Insert the included ER14505 AA Lithium Battery, ensuring the positive (+) terminal and negative (-) terminal match the markings on the D20.

3. After installing the battery, close the battery cover.

Registration

1. With the battery installed, press the button at the bottom of the D20 to wake it up.

Note: The LED on top of the D20 will pulse green when it is ready to register and will stay in this mode for 2 minutes before returning to sleep.

2. Open the Rhombus mobile app, tap "Menu" in the bottom right corner, and select "Register Devices."

3. Select the D20(s) you want to register.

Note: You can confirm the correct device via the serial number displayed on the app matches the one on the back of the D20.

Bluetooth

Bluetooth is a wireless technology standard used for exchanging data between devices over short distances.

BLE Range

For BLE connection with a compatible device, all Rhombus sensors can communicate via Bluetooth up to 100m under ideal circumstances. 

BLE range can be affected by different factors, including but not limited to:

• Obstacles: Physical obstacles such as walls, furniture, and other obstructions can weaken Bluetooth signals and reduce range.
• Environmental Conditions: Environmental factors such as humidity, temperature, and electromagnetic interference can affect the performance of the device.
• Interference: Bluetooth operates in the 2.4 GHz frequency band, which is also used by many other wireless technologies like Wi-Fi, cordless phones, and microwaves. Interference from these devices can degrade Bluetooth signals and reduce range.

BLE Signal Strength

BLE signal strength is referenced as RSSI, Received Signal Strength Indicator. A higher RSSI value like -10 (closer to 0) generally indicates a stronger signal, while a lower RSSI value, such as -85 (further from 0) indicates a weaker signal.

Signal strength can vary depending on factors such as distance, obstacles, interference, and the transmitting power of the Bluetooth devices involved. When evaluating BLE signal strength, it's important to consider these factors and ensure that the signal strength is sufficient for the intended application.

Web Console	Mobile App
Located in the second column of the devices tab sensor view. (Hover over this icon to display the RSSI value)	Located in the the list view on the sensors page.

D20 Sensing Range

The D20 has an approximate 20mm sensing range when the magnet is normal to the side face of the D20 containing the "magnet placement symbol."
The D20 has an approximate 13mm sensing range when the magnet is normal to the top face of the D20.
The D20 has an approximate 7mm sensing range when the magnet is normal to the side face of the D20 without any markings.

Hardware Installation

1 a). Fix the mounting bracket to the desired surface using the 2 mounting screws provided (drywall anchors included if needed).

We recommend attaching the bracket to the top of the door frame (on the opening side) to prevent accidental removal.

1 b). OPTIONAL: The included mounting adhesive can be used to attach the mounting bracket if screws are not desired.

2. Insert the D20 into the mounting bracket as shown with the “magnet placement symbol” facing the door side.

3. Rotate the D20 clockwise about the mounting bracket until you hear a click.

4. Attach the magnet to the door using the provided mounting adhesive.

5. For best results, ensure marking on the magnet lines up with the D20 "magnet placement symbol." In this position, the magnet should be less than 20mm away from the D20 for accurate readings.

Mounting Positions

The D20’s magnetic sensing range allows for different mounting options to be possible. Sample mounting positions are shown below for reference, with the D20 attached to the frame while the magnet is attached to the door.

Note that the sensing range will vary based on the chosen mounting position (see D20 Sensing Range).

Roll-Up Door Setup

The D20 features a built-in accelerometer that can be used with roll-up doors. When setting up, place the sensor on the roll-up door with the notch facing downward toward the ground when the door is closed. When the door is open, ensure the sensor is positioned sideways or at an angle. It's important to note that the magnet is not required for this setup and should be omitted from the mounting process if using the sensor in this manner.

In roll-up door mode, the D20 sensor detects changes in orientation from the magnet sensor mark facing down to the Rhombus logo facing down, rather than relying on the presence of a magnet as in normal operation mode. This setup means that doors designed in a castle door style, where the D20's orientation remains constant while the door moves up and down, are incompatible.

Additionally, the vertical placement of the D20 sensor on the roll-up door affects how far into the roll-up action the sensor will register the door as open or closed. Placing the D20 at the very bottom of the roll-up door means it won't register as open until the door is fully rolled up around the bend. Conversely, positioning the D20 at the top of the vertical portion of the roll-up door when closed allows it to detect the door opening sooner, as less of the door needs to retract to change the D20's orientation.

Open Door:

Closed Door:

Coiling Door Setup (3rd Party)

The D20 sensor can be used for a coiling roll-up door. However, this setup will require the implementation of several third-party components. Some of the materials used in this setup are not made by Rhombus; therefore, we cannot guarantee technical support for this setup.

Note: This setup does not use the included sensor magnet for the D20.

1. Mount the D20 to the door frame. The D20 can be mounted using fasteners or an adhesive. We recommend mounting with fasteners as they allow for future adjustments. However, in this example, we mounted a 90° bracket to the frame and adhered the D20 to the bracket using Gorilla Glue caulk.

2. Position the rectangular neodymium magnet just below the door fold to prevent damage when the door is coiled. You may use your preferred magnet, but the magnet used in this example can be found here: Strong Neodymium Rectangular Magnet.

Note: Before permanently mounting the magnet to the door, ensure the magnet mounting position properly registers the open/closed status in the Rhombus Console.

Unregistering

Sensors can only be unregistered from the mobile app. You must be logged into the organization of the sensor(s) you want to unregister.

Note: To unregister a sensor, a BLE-compatible device must be connected to the network and be within range of the sensor. Sensors must be unregistered before the Rhombus gateway device is unregistered.

1. Open the Rhombus mobile app, tap "Menu" in the bottom right corner, then tap "Utilities."

2. Tap "Unregister Sensors."

3. Select the sensor(s) you want to unregister and complete the flow.

Troubleshooting

Ensure a BLE Gateway is present when connecting a sensor. See the list of compatible devices that can be used as a gateway. 

LED Indicators

Troubleshooting Steps

Helpful Links

• Creating and Assigning Alert Policies
• User-Based Alert Notifications

Contact Support or Sales

Have more questions? Contact Rhombus Support at +1 (877) 746-6797 option 2 or support@rhombus.com.

Interested in learning more? Contact Rhombus Sales at +1 (877) 746-6797 option 1 or sales@rhombus.com.