When you protect a door or window, start with the opening itself—not with a generic sensor list. Record how the opening moves, what the frame and leaf are made of, where the two surfaces meet when closed, and what the alarm system should do when the opening changes state. Those four observations usually tell you more than a product label alone.
A door contact detects whether a protected opening is open or closed. It does not tell you whether a lock bolt is engaged. For an installer, the useful result is a repeatable event: the contact changes state as the door or window moves, the paired Hub receives that event, and the configured zone applies the behaviour required for that area. This guide follows that path from selection to final-position testing.
What does a door contact actually detect?
A typical magnetic contact has a larger main body and a smaller magnet. When the door or window is closed, the two parts sit in their intended relationship. Opening the protected leaf changes that relationship and the contact reports an open event. Closing it reports the return to the closed state.
Think of the event path as:
Opening movement → contact state → Hub zone → configured local, App or monitoring behaviour
The contact reports the opening state; the zone and the rest of the alarm system determine what happens next. This distinction matters when a project requires a door-open alert, an entry delay or a local alarm path. Name the zone for the actual opening—such as “front entrance” or “stockroom rear door”—so a later event is meaningful to the service team.
Start with the opening, then choose the device
Choose a contact only after you have described the opening and the installation surface. The first record should include:
- opening type: hinged door, sliding door, casement window or another protected opening;
- frame and leaf material, including nearby metal that could affect mounting or radio conditions;
- movement and closed geometry: which part stays fixed, which part moves, and how the two surfaces align;
- available mounting space and whether the device can be reached for battery or service work; and
- the zone behaviour the project needs when the opening changes state.
For a timber door with a clean frame, a surface-mounted contact may be straightforward. A metal frame may require more careful positioning and a final signal check. A sliding window or an offset opening can place the two parts on different planes, so the mounting method must follow the real closing movement rather than an idealised front view.
Use the observations to make the first selection decision:
| What you see on site | Selection direction | Why it matters | Verify after selection |
|---|---|---|---|
| Hinged, stable opening | Start with a surface-mounted contact that follows the fixed-frame to moving-leaf path | The two parts can stay aligned through a predictable movement | Open and close fully at the final position and confirm the state change |
| Sliding or offset opening | Choose a form and mounting method that fits the two real closing planes | Sideways travel or different heights can defeat a front-facing layout | Test the complete slide or offset, including the closed end position |
| Timber/uPVC in a controlled indoor location | A surface or wireless retrofit can keep the installation simple when the approved model fits | The frame usually offers workable mounting and service access | Confirm alignment, housing stability and the zone event after mounting |
| Nearby metal or a metal frame | Keep the choice tied to the approved model and plan a final signal check | Metal and surrounding structure can significantly weaken or destabilise the wireless link to the Hub; a correct reed/magnet state does not by itself show that the link is reliable | With the door closed and open at the final position, repeat the event test and check the signal from that position |
| Exposed/outdoor condition | Use only a device and method explicitly approved for that environment | Environment suitability is model- and project-specific | Confirm approved placement, physical state and the included alarm path |
| Opening-only detection is sufficient | Start with a standard door/window contact | The project needs an open/closed event, not another detection function | Confirm the zone behaviour matches the required event |
Advanced selection note
If the project needs shock, tilt or anti-masking information, or if drilling, a concealed route, a fire-door finish or maintenance access changes the installation choice, pause for project and product confirmation. Compare surface, recessed or wired methods only within the approved model and opening constraints; do not assume a basic opening contact provides an additional function. For an exact Roombanker model, continue to the Door Magnetic Sensor product page after recording those conditions.
The practical decision is straightforward: use a standard opening contact when the geometry is stable and open/closed detection is all the project needs. Choose another form or mounting method when the opening moves on another plane or the surface and access rules require it. Return to project design confirmation when an additional detection function is part of the requirement.
Mount the main body and magnet on the correct sides
For the Roombanker RBSS-MC1 example, mount the larger main body on the fixed door or window frame and the smaller magnet on the moving leaf. Place them near the opening or handle side, away from the hinge side, and align them according to the model instructions and the actual movement. Other contact models must follow their own approved installation instructions.
For this RBSS-MC1 arrangement, the frame stays still while the leaf moves away. Do not reverse the parts, put both pieces on the same side, or place them on the hinge side simply because it looks tidy. Keep the housing clear of collision, bending and routine contact with the frame, and leave enough access for inspection or battery service. If you are using another model, confirm which part is fixed, which part moves and which orientation its instructions require.
Consider a shop with a metal-framed entrance. The main body is fixed to the frame and the magnet follows the moving leaf near the handle side. Before finalising the position, open the door slowly, open it normally, and close it fully. Confirm both layers separately: the reed/magnet must report the right open and closed states, and the Hub must show a suitable signal result at the final position. If the frame or nearby metal forces an offset, judge the pair by the real movement and the approved model instructions—not by a trigger distance copied from another contact.
For a concrete product example, watch the RBSS-MC1 installation and App demonstration below. It shows the two-part contact and its App workflow; apply the selection and final-position checks in this guide to the actual opening before accepting the installation.
When you are ready to install that model, follow the RBSS-MC1 quick-start guide for its exact operating steps.
Pair the contact, name the zone and configure the area
After the physical position is workable, pair the contact with the project Hub and assign it to a recognisable zone. The zone name should tell the next person which opening is involved without consulting a drawing. Then configure the behaviour required for that scenario: for example, whether the opening is active while the area is armed, whether an entry delay is needed, and which local, App or monitoring path is included.
Pairing confirms that the Hub can enrol the device. It is not the final installation check. A contact can pair beside the Hub and still need a new test after it is moved to a metal frame, a back room or another floor. Treat the final installed position as the place where the project decision is made.
Test the contact at its final position
At the final position, run the movement and event checks the project actually includes:
- Check the closed state with the door or window fully shut.
- Open it slowly and confirm that the zone changes to open.
- Open it at the normal user speed and confirm the same event path.
- Close it again and confirm that the zone returns to closed.
- Check the signal result, zone identity, tamper indication and the local, App or monitoring path included in the project.
Repeat the test after any change to the mounting surface, orientation or Hub position. A successful pairing screen is useful evidence, but it does not replace a movement test at the place where the contact will operate every day.
When the door contact is one part of a larger commissioning job, use the wireless alarm installation workflow to place this device check within the wider Hub, zone, response-path and handover sequence.
For a small factory with a sliding service door, the closed position may look correct while the leaf shifts sideways during travel. Test the full slide, not only the first few centimetres, and confirm that the contact reports the intended state at the actual end position. Record the result with the opening name and the final mounting arrangement.
Troubleshoot by the symptom you can see
The door is closed, but the zone still shows open
First inspect the physical relationship. Check that the main body is on the fixed frame, the magnet is on the moving leaf, and both parts remain aligned when the opening is fully closed. Look for a shifted adhesive mount, a frame edge that prevents the intended position, or movement that changes the alignment. Correct the mounting, then repeat the closed/open test at the final position.
The door opens, but no open event appears
Check that the leaf actually moves the magnet away from the main body and that the contact is assigned to the intended zone. Re-run a slow opening test and confirm that the Hub is receiving the event. If the signal result is poor or unstable at the installed location, first check whether the contact is directly against metal or screened by a large metal surface. Then assess an alternative position without breaking the correct opening geometry, review the Hub position and propagation path, and return to project design if the result remains unsuitable.
Events appear only sometimes
Compare the complete movement, not just one snapshot. Inspect for vibration, a loose mounting surface, a sliding or offset path, and changes in the nearby environment. Confirm the contact state at several normal openings and closings, then check the signal and zone behaviour. Change one physical or configuration variable at a time so the next test shows what actually improved.
The device went offline after installation
Start with the final position and the power condition. Check that the housing is secure, the battery is seated as specified for the model, and the Hub path is appropriate for the building layout. If the project uses an RB Link installation or signal test, capture that result together with the zone name and position before escalating the wireless issue.
The App shows an event different from the local test
Confirm that the event came from the intended zone and that the App is showing the same project state. Then check which local, App or monitoring path was included in the design. Do not assume that a different display means the contact is physically misaligned; first separate the contact state, Hub event, zone configuration and downstream behaviour.
If the symptom affects several devices, the Hub or more than one response path, move from this door-specific check to the wireless alarm troubleshooting guide and diagnose the system layer before changing the contact again.
What should be in the handover record?
Use this handover card for each opening:
- Opening identity: door/window name, type and frame/leaf material.
- Final mounting: main body and magnet positions, orientation and access condition.
- Zone: recognisable zone name and configured behaviour.
- Movement/state: closed, slow-open, normal-open and close-back checks.
- Signal/tamper: final-position signal result and rear-tamper result.
- Response path: local, App or monitoring path tested, plus any exception to resolve.
Choose the next technical step
If you still need to select a specific device, review the Door Magnetic Sensor product page against the opening record you made at the start. If the question is about a metal frame, a distant Hub or an intermittent radio result, continue with the wireless alarm signal stability guide. For App onboarding and project software context, see RB Link.
The practical sequence is simple: describe the opening, choose the matching approved device, mount the main body on the fixed frame and the magnet on the moving leaf near the opening side, configure the zone, then test the complete event path at the final position. That sequence gives the project a door-contact result that another installer can understand and check.