Reed Switch Whitepaper


The reed switch is an electrical switch operated by applying a magnetic field. Without the magnetic field, the switch is open, with the magnetic field, the switch closes. This sensor allows Simple Hardware devices to cover a great number of use cases - when combined with a magnet.

The reed switch replaces the button functionality in the SimpleIndustry and SimpleMeter devices and is used to trigger downlink!

There are three API 6 user modes that work with the sensor:

  • Reed switch on/off

  • Reed switch counter

  • Reed switch pipeline

Each of these modes covers a different business logic by having sending different data based on different triggers. Let's have a closer look.

IMPORTANT: The reed switch functionality below works exactly the same with switch/dry contacts!

Reed switch on/off

How it works: When the reed switch closes, a message is sent immediately. When the magnetic field is no longer present and the switch opens, a different instant message is sent. Very simple!

Reed switch on/off is also available in three different WiFi versions. You can read about them right here!

Reed switch counter

How it works: The device will count the number of times the reed switch has closed (number of magnetic field presences/magnet rotations). You can choose the trigger of the message: either it's time (number of switches in e.g. one hour) or the exact count (message sent after e.g. 50 switches.)

Reed switch pipeline

How it works: The device will measure how long the reed switch was open and then how long it was closed. This will then be reported in a message that contains a total of 8 time periods: 4 for both states. E.g. reed switch closed for 12 minutes, then opened for 10 minutes, then closed again for 8 minutes, etc.

Reed switch modes comparison table

ModeReed switch on/offReed switch counterReed switch pipeline

Mode hex (API 6)




WiFi versions available


Message trigger

switch open/closed

time/count reached

time - pipeline full

Message availability


customizable as per settings

when pipeline is full

Appended payload possible

✔️ (not in WiFi versions)

Reed switch-based modes can be fine-tuned with these downlink registers:

Register nameRegister hexRegister value rangeWhat it is and what it doesUseful for

Sleep time



Time after record/message during which the device will ignore any sensor input.

Reed switch on/off, Reed switch counter

Reed switch measurement period interval



How often the processor wakes the sensor up and asks for data input - how often the sensor measures.

All reed switch modes

Reed switch pipeline time threshold for exponent selection



Please see the mode documentation for detailed information.

Reed switch pipeline

Reed switch detection delay



How long should the change of state last before the message is triggered or data recorded.

All reed switch modes

Reed switch counter count trigger


Number 1-255

After how many reed switches should the message be sent.

Reed switch counter

Reed switch counter time trigger



After how long should the message be sent.

Reed switch counter

Here's the API 6 table for more information!

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