> For the complete documentation index, see [llms.txt](https://www.multi-module.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.multi-module.org/using-the-module/protocol-details/hott.md).

# HoTT

## Details

**Protocol Number:**  57\
**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](/using-the-module/frequency-tuning.md) for more details.
{% endhint %}

## Notes

**Models:**  Graupner HoTT receivers (tested on GR-12, GR-12L, GR-16, and Vector)

Receiver feature configuration can be performed using the OpenTX script **Graupner HoTT.lua**.

Basic telemetry is available on OpenTX 2.3.3+ with receiver voltage, receiver temperature, RXRSSI, RX LQI, TX RSSI and TX LQI.

Lower TX LQI values indicate better link quality. TX LQI is a good indicator of how well the module is tuned.

{% hint style="warning" %}
You must use a different Receiver Number for each receiver.  A maximum of 64 Hott receivers are supported.
{% endhint %}

{% hint style="danger" %}
Failsafe **must** be configured once with the desired channel values (hold or position) while the receiver is up (wait 10+ seconds for the receiver to learn the config) and then failsafe **must** be set to RX/Receiver otherwise the servos will jitter!
{% endhint %}

## Channel Assignment

| CH1 | CH2 | CH3 | CH4 | CH5 | CH6 | CH7 | CH8 | CH9 | CH10 | CH11 | CH12 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | ---- | ---- | ---- |
| CH1 | CH2 | CH3 | CH4 | CH5 | CH6 | CH7 | CH8 | CH9 | CH10 | CH11 | CH12 |

## Sub Protocols

### 0 - Sync

Recommended for best telemetry performance.

### 1 - No\_Sync

Telemetry compatibility mode which can be used when Sync does not work due to an old firmware on the RX. 

{% hint style="warning" %}
You should  upgrade your receivers/sensors to the latest firmware versions: <https://www.rcgroups.com/forums/showpost.php?p=44668015&postcount=18022>
{% endhint %}