How to Enroll a Wireless Sensor and Confirm Its Signal

Why this matters

A wireless sensor tested on the kitchen counter next to the panel proves almost nothing. It is two feet from the receiver with nothing in the way. Mounted on a basement window behind a ductwork trunk and a foil-faced insulation board, the same sensor may reach the receiver on some transmissions and not others, and the system will find out on a cold night with a supervision trouble at 3 a.m., or worse, miss the one transmission that mattered. Enrollment is where the panel learns the sensor exists; the signal reading is where you learn whether it can be heard from where it lives. This card does both and leaves a record the next tech can use: one line per sensor, with the signal taken from its mounted spot.

For how supervision windows and battery reporting work once a sensor is enrolled, see related: Wireless Sensor Supervision, Signal and Battery Life.

Start state

You need: the sensors, still in their packaging with battery tabs in; the panel's programming manual open to wireless enrollment; the installer code; a pen and the enrollment record (below); a step ladder for high mounts; the mounting hardware.

Check before you begin:

• Account on test. Enrolling and tripping sensors sends faults, tampers and sometimes alarms. See related: How to Put an Alarm Account on Test and Take It Off.
• The sensors match the receiver. Panels and receivers are built for one or more sensor families; a sensor from another family will not enroll however hard you try. The receiver's documentation lists what it hears.
• The zone list from the survey, with the zone number, zone type and location name for each sensor already decided. Enrollment is not the time to invent names.
• Who has the installer code, and that it is handled per the shop's rule. See related: The Installer Code and Customer Passcode Handling SOP.

Hazard: the lithium cells many sensors use can deliver enough current into a short to heat quickly; do not carry loose cells in a pocket with keys or coins, and do not leave spare coin cells where a child can reach them, because a swallowed coin cell causes severe internal injury within hours.

The record you are filling in

Every step below fills one column of this sheet. It goes in the job file and a copy stays in the panel can.

WIRELESS ENROLLMENT RECORD
Site: 2-story colonial, basement   Panel: hybrid
Receiver: built into panel, 1st floor laundry
Signal scale per this panel: 0 to 5, 3 or better OK

Zone Serial    Type        Location name     Bench Mounted
 9   ...4417   Entry/exit  Front door          5     5
10   ...4422   Perimeter   Kitchen window E    5     4
11   ...4431   Perimeter   Kitchen window W    5     4
12   ...4436   Perimeter   Basement window E   5     1
     relocated 4 in down jamb, away from duct:       3
13   ...4440   Perimeter   Basement window W   5     3
14   ...4458   Interior    Upstairs hall mot.  5     4

Mounted reading = lowest of 3 transmissions
Labeled inside cover with zone no.: yes, all 6
Tech: R.O.   Date: 10/14   Account on test 09:10-11:40

The signal scale and threshold in that sheet belong to the panel in this example. Panels report signal differently (bars, a number out of a fixed scale, a percentage, or a pass/fail), and the acceptable level is whatever that panel's or that receiver's documentation says. Write the scale and the threshold at the top of the sheet so the numbers mean something to the next reader.

The steps

1. Enter the panel's wireless learn mode with the installer code. On most panels this is a programming menu that waits for a serial number or a transmission. Leave the other sensors packed with their battery tabs in. Why: a learn mode listening for "the next transmission it hears" will take whichever sensor speaks first, including one in the box on the table, one you jostled in your bag, or, in a townhouse, a neighbor's sensor of the same family.

2. Enroll one sensor, by serial number or by tripping it.

• By serial: type the serial printed on the sensor or its label. Read it twice; a transposed digit enrolls a sensor that does not exist, and the real one never reports.
• By tripping: pull this one sensor's battery tab and trigger it (open its magnet, press its tamper, or as the sheet directs) so it transmits. The panel captures its serial. Copy the last four of the serial onto the record either way, so a later swap can be matched to the right zone.

3. Set the zone type and the location name now, from the survey's zone list. The zone type decides what happens when the sensor trips; the name is what the central station reads to a responder. A zone named "Zone 12" or "window" sends an officer to guess. See related: Zone Types and What Each One Does When Tripped.

4. Confirm the panel sees the sensor at the bench: trip it, see the zone fault and restore at the keypad. Write the bench signal in its column. A sensor that reads poorly two feet from the receiver is defective or the wrong family; stop and swap it before it goes on a wall.

5. Repeat 2 to 4 for each sensor, then exit learn mode. One at a time. An enrollment session with six sensors unpacked at once is how two sensors end up swapped between zones, which nobody notices until a responder is sent to the kitchen for a basement window.

6. Mount each sensor in its planned spot. Contact on the frame, magnet on the moving part; for door and window placement see related: How to Install Surface Contacts on Windows and Sliders, and for motion see related: How to Place and Aim a Motion Detector. Close the cover fully. An open cover changes the antenna's surroundings and leaves the tamper faulted.

7. Read the signal from the mounted spot, with everything closed. Doors and windows shut, the cover on the sensor, the panel's door closed, the closet door closed if the panel is in one. Use the panel's signal or RF test mode, trip the sensor three times a few seconds apart, and record the lowest reading. Why the lowest of three: radio reception from a fixed spot varies between transmissions as people move, doors swing and reflections shift. A single good reading can be a lucky one; the lowest of three is closer to what the panel will hear on a bad night.

8. Act on any reading below the threshold before you leave. In this order, because each costs more than the one before: move the sensor a few inches on its frame or rotate it, away from metal; move the obstruction if it is the customer's (a metal shelf against the window); add a repeater or a second receiver if the panel supports one; hardwire that opening. Re-read after every change.

9. Label each sensor inside its cover with its zone number, and leave a copy of the record in the panel can. The next tech replacing a battery can then match the sensor to the zone without tripping every sensor in the house.

Worked example: the basement window that read 1

The sheet above is from a two-story colonial with a basement. Six sensors enrolled at the bench; every bench reading was 5 of 5. Mounted readings, lowest of three transmissions each:

• Five sensors read 3 or better from their mounted spots: front door 5, both kitchen windows 4, basement west window 3, upstairs hall motion 4.
• Basement east window read 1 on two of three transmissions and 2 on the third. The recorded value is the lowest, 1, below this panel's threshold of 3.

Finding the cause. The basement east window sits behind a supply trunk running along the rim joist, and the band joist above it was insulated with foil-faced board. The receiver is on the first floor directly above, so the sensor's signal had to pass through or around both. The west window, with no duct in front of it and the same insulation, read 3.

What was tried, in order:

1. Rotating the sensor 90 degrees on the jamb: still 1 at the lowest.
2. Moving it 4 inches down the jamb, below the bottom of the duct, out of the pocket behind the metal trunk so its signal could reach the open basement and the floor above: lowest of three was 3. That meets the threshold.

The installer stopped at step 2, recorded the relocated position and the new reading on the sheet, and noted that this window sits at the threshold with no margin. A repeater was not added, but the note means the next service tech who sees a supervision trouble on zone 12 knows where to start.

Had the relocation not reached 3, the next options were the repeater the panel supports or a hardwired contact on that window, since the basement ceiling was unfinished and a run would be short. The wrong option is to accept a 1 and leave: zone 12 would have reported supervision trouble intermittently through the winter, and a burglar using that window could have gone unreported on exactly the transmission the panel missed.

Finish test

Every sensor reads at or above the panel documentation's acceptable level, as the lowest of three transmissions, from the spot it is mounted, with everything closed. Every sensor's zone faults and restores at the keypad, and the fault and restore arrive on the central station's history with the right zone number and name. The record lists all of them, and each sensor is labeled.

Run the count both ways before closing out: six sensors on the zone list, six lines on the sheet, six labels, six zones on the station's list. Then take the account off test, and confirm with the station that it is back to normal.

When the method changes

A takeover of an existing wireless system. The sensors are already enrolled in a panel you may not have the code for, and they may be a family your new panel's receiver cannot hear. Confirm compatibility before quoting the takeover. See related: How to Take Over an Existing Alarm System.

Life-safety sensors. Wireless smoke and CO detectors enrolled on a combination panel are fire-side devices with their own listing and installation rules under NFPA 72, in the edition adopted, often separately licensed. See related: How to Add a Monitored Smoke or CO Detector to an Alarm Panel.

Large or metal buildings. Steel framing, metal siding and long distances change everything: plan receivers and repeaters at the survey, from readings taken on site, not from the receiver's stated range.

References

• Panel and receiver manufacturer's programming manual: enrollment, signal test mode and acceptable signal level
• Sensor manufacturer's instruction sheet: battery type, mounting and tamper
• See related: Wireless Sensor Supervision, Signal and Battery Life
• See related: How to Put an Alarm Account on Test and Take It Off
• See related: How to Install Surface Contacts on Windows and Sliders