# Tracking Device, Physical Connections

Each tracking device has to be connected directly to the Reality Engine, where the tracking data is going to be utilized. Usually tracking devices send the data using the following link types:

* Serial port (usually RS422 for longer cables)
* Ethernet port (UDP protocol, each device lets you choose which port and IPs to send data)

### Serial Port Connection <a href="#trackingdevice-physicalconnections-serialportconnection" id="trackingdevice-physicalconnections-serialportconnection"></a>

Some tracking devices provide data over serial port. Usually the serial connection protocol from these devices are “RS422”, which allows longer cabling. Most modern computers do not have a serial port available, in such cases we suggest that you use a certified USB-to-serial converter, which is “Moxa UPort 1150” currently. Be sure to set the serial port device driver to “low latency” mode.

<div align="left"><img src="/files/5t5ahzJOUfrMku4SMEVW" alt=""></div>

{% hint style="info" %}
Be sure to use the certified converter whenever possible. But if you use another converter, you have to make sure that it works in the lowest latency mode. Serial port driver settings and qualities are extremely important for the consistency of tracking data and delays.
{% endhint %}

### Ethernet Port Connection <a href="#trackingdevice-physicalconnections-ethernetportconnection" id="trackingdevice-physicalconnections-ethernetportconnection"></a>

Tracking devices which provide data over Ethernet port send the data over UDP. Make sure that software such as a Firewall is not blocking the data sent by the tracking device. Some tracking devices can send data to multiple IP targets, which might be useful for redundant engine configurations.

<div align="left"><img src="/files/s8DhiSbZrfbp4kd7fN2H" alt=""></div>

### External Reference Signal <a href="#trackingdevice-physicalconnections-externalreferencesignal" id="trackingdevice-physicalconnections-externalreferencesignal"></a>

The tracking device, camera signal and engine video output should be synchronized to the same reference signal. Any tracking device needs this sync signal in order to provide synchronized tracking data with the camera signal.

{% hint style="warning" %}
Be sure to run your tracking device at the same frame rate as your camera frame rate.
{% endhint %}


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