# FrSky X (D16)

## Details

**Protocol Number:**  15\
**Autobind:**  No\
**Channel Re-mapping:**  No\
**Extended Limits:**  Yes\
**Failsafe Support:**  Yes\
**Receiver Match:**  Yes\
**Telemetry:**  Yes\
**Option Value:**  Frequency fine tuning

{% hint style="danger" %}
Frequency tuning is required for this protocol.  See the [Frequency Tuning page](https://www.multi-module.org/using-the-module/frequency-tuning) for more details.
{% endhint %}

## Notes

**Models:**  FrSky D16 receivers, including X4R, X6R, X8R, XSR, XM+, and SxR, running **ACCST v1 firmware**.  D16 compatible receivers.

{% hint style="danger" %}
FrSky receivers running ACCST v2 firmware should use the [**FrSkyX2** protocol](https://www.multi-module.org/using-the-module/protocol-details/frsky-x2) - they are not supported by this protocol.
{% endhint %}

Full telemetry is supported, including bi-directional capabilities, enabling LUA scripts to be used to configure SxR receivers and Betaflight parameters (for example).

Listen Before Talk (LBT) is supported. Use the EU/LBT sub-protocols for receivers running EU / LBT firmware.

{% hint style="success" %}
In OpenTX the FrSky X protocol is accessed as **FrSky**, with subprotocol **D16**. 

The **FrSky** protocol also has subprotocols for ACCST v1 D16 receivers in FCC and EU/LBT modes and D16 8 channel mode, as well as [FrSky V](https://www.multi-module.org/using-the-module/protocol-details/frsky-v) receivers and [FrSky D (D8)](https://www.multi-module.org/using-the-module/protocol-details/frsky-d) receivers.
{% endhint %}

### Binding

When binding a D16 receiver the radio will prompt you to choose the bind configuration.  This prompt allows you to configure the receiver outputs, in the same way that it can be configured with physical jumpers placed on the PWM output pins during bind.

![D16 Binding Options](https://3357080223-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LwnWq9OVxVlVodwNBnH%2F-MBIkO4k16Mur4REFiAT%2F-MBImAuKtKnd7pSmoDip%2Fd16-binding.png?alt=media\&token=fed16e19-4f65-4927-bd5c-1fef07385ad8)

The selection you make determines which channels will be output on the PWM pins of the receiver, and whether telemetry is on or off.  The remaining channels will be output on the SBUS port.

#### For Example:

`Ch1-8 Telem ON` will output the radio channels 1-8 on the receiver's PWM pins and channels 9-16 on the SBUS port, with telemetry enabled.  This configuration could typically be used on a model with servos connected directly to the receiver.

`Ch9-16 Telem ON` will output the radio channels 1-8 on the SBUS port and 9-16 on the receiver's PWM pins, with telemetry enabled.  This configuration could typically be used on a model with a flight controller connected to the SBUS port and accessories (such as a camera gimbal) connected to the PWM pins.

Refer to your receiver documentation for more information.

## Sub Protocols

### 0 - CH\_16

FCC protocol, 16 channels @18ms.

| CH1 | CH2 | CH3 | CH4 | CH5 | CH6 | CH7 | CH8 | CH9 | CH10 | CH11 | CH12 | CH13 | CH14 | CH15 | CH16 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | ---- | ---- | ---- | ---- | ---- | ---- | ---- |
| CH1 | CH2 | CH3 | CH4 | CH5 | CH6 | CH7 | CH8 | CH9 | CH10 | CH11 | CH12 | CH13 | CH14 | CH15 | CH16 |

### 1 - CH\_8

FCC protocol, 8 channels @9ms.

| CH1 | CH2 | CH3 | CH4 | CH5 | CH6 | CH7 | CH8 |
| --- | --- | --- | --- | --- | --- | --- | --- |
| CH1 | CH2 | CH3 | CH4 | CH5 | CH6 | CH7 | CH8 |

### 2 - EU\_16

EU-LBT (listen before talk) protocol, 16 channels @18ms. 

| CH1 | CH2 | CH3 | CH4 | CH5 | CH6 | CH7 | CH8 | CH9 | CH10 | CH11 | CH12 | CH13 | CH14 | CH15 | CH16 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | ---- | ---- | ---- | ---- | ---- | ---- | ---- |
| CH1 | CH2 | CH3 | CH4 | CH5 | CH6 | CH7 | CH8 | CH9 | CH10 | CH11 | CH12 | CH13 | CH14 | CH15 | CH16 |

### 3 - EU\_8

EU-LBT (listen before talk) protocol, 8 channels @9ms. 

| CH1 | CH2 | CH3 | CH4 | CH5 | CH6 | CH7 | CH8 |
| --- | --- | --- | --- | --- | --- | --- | --- |
| CH1 | CH2 | CH3 | CH4 | CH5 | CH6 | CH7 | CH8 |

### 4 - Cloned

Uses the identifier learnt from another FrSky radio using the FrSkyRX/CloneTX mode.\
16 Channels

### 5 - Cloned\_8

Uses the identifier learnt from another FrSky radio using the FrSkyRX/CloneTX mode.\
8 Channels