> For the complete documentation index, see [llms.txt](https://wiki.inels.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://wiki.inels.com/inels-home/inels-wireless/how-programming-works.md).

# How programming works

The one idea every iNELS Wireless unit follows. Learn this page once and every unit manual becomes a lookup.

*Part 1 — Understand the system. Read* [*Transmitters, receivers and gateways*](/inels-home/inels-wireless/transmitters-receivers-and-gateways.md) *first.*

This page is about **direct pairing**: teaching a receiver to obey a transmitter button by hand. Every unit works the same way, so once you understand this page every other page is a lookup: *how long do I hold PROG on this unit, and how many times do I press?*

(For the app, cloud and automation through a gateway, see [System units and gateways](/inels-home/inels-wireless/devices/system-units.md).)

***

## Transmitter and receiver

| Role            | What it does                                                        | Examples                                                                                             |
| --------------- | ------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------- |
| **Transmitter** | Sends a command when a button is pressed or a detector is triggered | Wall controllers RFWB, RFGB · key fobs RF KEY · detectors RFMD, RFWD, RFSF · input modules · sensors |
| **Receiver**    | Switches, dims or moves the load                                    | Switch units RFSA, RFSAI · dimmers RFDEL, RFDA · shutter units RFJA                                  |

Some products are both at once — for example RFSK-21/MPW (button controller with a relay) or the RFSW and RFDW glass controllers with built-in outputs.

**Pairing** teaches a receiver to obey one transmitter button. The memory is **in the receiver**, not in the transmitter. That has three consequences:

* **Clearing is always done on the receiver.** The transmitter does not know what it is paired to.
* **One button can control many receivers** — pair it to each of them.
* **One receiver accepts many buttons**, up to its channel limit (RFSAI-61B-SL: 25 buttons; RFSAI-62B-SL: 12 per output).

```mermaid
flowchart LR
    B1["RFWB-40 button 1"] -->|4× impulse relay| U1["RFSAI-61B-SL<br/>hall light"]
    B1 -->|2× switch on| U2["RFSAI-62B-SL output 2<br/>porch light"]
    K3["RF KEY button 3"] -->|3× switch off| U1
```

## The number of presses chooses the function

While the receiver is in programming mode, you press the transmitter button **N times**. N is the function.

| Presses | Switch units           | Dimmers       |
| ------- | ---------------------- | ------------- |
| 1×      | Pushbutton             | Light scene 1 |
| 2×      | Switch on              | Light scene 2 |
| 3×      | Switch off             | Light scene 3 |
| 4×      | Impulse relay (toggle) | Light scene 4 |
| 5×      | Delayed off            | Sunrise       |
| 6×      | Delayed on             | Sunset        |
| 7×      | —                      | On / off      |
| 8×      | —                      | Switch off    |

Full descriptions and graphs: [Appendix B](/inels-home/inels-wireless/appendix-b-functions-by-number-of-presses.md).

{% hint style="warning" %}
**Leave about 1 second between presses.** The unit manuals require at least 1 s between commands. Pressing quickly is the most common reason a unit ends up with the wrong function.
{% endhint %}

## The PROG button: how long you hold it decides what happens

Every receiver has one **PROG** button. It does four different jobs depending on how long you hold it:

| Hold                      | What happens                                                      | LED                                     |
| ------------------------- | ----------------------------------------------------------------- | --------------------------------------- |
| Short press (< 1 s)       | Manual on/off of the output — or, in programming mode, **finish** | Output toggles                          |
| *Enter programming* time  | Receiver waits for a transmitter button                           | Flashes once per second                 |
| *Clear one button* time   | Next button you press is removed                                  | Flashes 4× per second                   |
| *Clear whole memory* time | Factory reset — all buttons removed                               | Flashes 4× per second, then every 0.5 s |

{% hint style="danger" %}
**The times are different on different units.** A single-channel RFSAI-61B-SL enters programming at 2 s and starts *clearing* at 5 s. A two-channel RFSAI-62B-SL needs 3–5 s to enter programming. Always look the unit up in [Appendix A](/inels-home/inels-wireless/appendix-a-prog-button-times.md) first.
{% endhint %}

## The LED tells you where you are

| LED on the receiver               | Meaning                                              |
| --------------------------------- | ---------------------------------------------------- |
| Flashes once per second           | Programming mode — waiting for a transmitter button  |
| Short flash at each press         | Command received                                     |
| Flashes twice per second          | Timing mode — measuring a delay time                 |
| Flashes 4× per second             | Clear mode                                           |
| Flashes every 0.5 s (up to 4 min) | Memory cleared, receiver waiting in programming mode |
| 3 blinks when you finish          | Memory function **on**                               |
| One long light when you finish    | Memory function **off**                              |

These patterns come from the RFSAI-xxB-SL manual. Most switch units and dimmers behave the same; the unit's own page lists any differences.

## Transmitter generations

Newer transmitters have a **pairing button** and a pairing symbol on the back. Older ones do not: they are put into pairing by re-inserting the battery, and the oldest units need **compatibility mode**. All procedures are in the [Pairing reference](/inels-home/inels-wireless/pairing-and-configuration.md).

## Direct pairing and gateways together

Direct pairing is the base of every installation. A gateway is added **on top** when you want the app, the cloud, scenes or automation.

| Method             | Tools                                               | Use it for                                                                                                                       |
| ------------------ | --------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------- |
| **Direct pairing** | Transmitter + receiver PROG button                  | Everyday switching: buttons, detectors, kits, small installations — tutorials 1–8                                                |
| **Gateway**        | eLAN-204, eLAN-103 or RFTC-3 + app or web interface | App and cloud control, scenes, timers, higher logic and automation. Receivers are added using the address printed on their front |
| **Service tools**  | RFAF/USB service key + PC, RF Touch-2               | Advanced settings, e.g. switching on a unit's repeater function                                                                  |

The methods combine: a receiver paired directly to a wall button can also be added to a gateway, so the button keeps working even if the network is down.

## Range

Range is up to **200 m in open space**. Indoors, every wall takes some of the signal:

| Material                            | Signal that gets through |
| ----------------------------------- | ------------------------ |
| Wooden structures with plasterboard | 80–95 %                  |
| Ordinary glass                      | 80–90 %                  |
| Brick walls                         | 60–90 %                  |
| Reinforced concrete                 | 20–60 %                  |
| Metal partitions                    | 0–10 %                   |

* Never install units in metal boxes or in switchboards with metal doors.
* Keep at least **1 cm** between units.
* If the signal is too weak, add an **RFRP-20** repeater, or switch on the repeater function of an RFIO2 unit in between.

***

## What you learned

* The receiver remembers; the transmitter just sends.
* Number of presses = function.
* PROG hold time = what the receiver does — and it differs per unit.
* The LED tells you which mode you are in.
* A gateway adds app, cloud and automation on top.

**Next:** [Pairing reference](/inels-home/inels-wireless/pairing-and-configuration.md) for every pairing case, or go straight to [Tutorial 1 — your first button and light](/inels-home/inels-wireless/tutorial-1-your-first-button-and-light.md).