Summit Bridge

To use Summits Timers, we recommend using a Zone4 Serverbox which provides a stable connection to collect and process times even if the internet is intermittent or non-existent. This Summit Bridge guide is for users who do not have a ServerBox available or want to transmit Summit times over cellular distances through a tethered laptop, or who have stable enough internet connection to trust it over the time required for a race.


Wireless Summit Timers require a serial connection over a 900 MHz wireless signal to a base station modem in order to communicate.  The base station modem must be connected to a PC running software to handle that serial communication.

Just like a base station modem, wired summits need that same connection to a PC via serial cable in order to transmit times. The summit bridge is a Chrome browser based feature that uses the browsers ability to connect to serial ports, and collects that serial data and converts it into web data for use in the Zone4 timing application.


To start using the summit bridge you will need a summit timer, RF modem, and any necessary cables to plug the RF modem into your computer’s USB port. On the PC, login to your club and click the “Timing Devices” section from your club overview

Then in the top right corner there is a “”. Click there to see the “Experimental Summit Bridge“.

If this is your first time in the the Summit Bridge application, click the … menu on the right and click “Summit Settings” and ensure that the highest device number is correct.

Once closing the Summit Settings, press the “Connect to …” button. Here you will be prompted with a window that will look something like this.

On a MacOS, it may appear as this:

If “No compatible devices found” is displayed then either the modem isn’t plugged in right, or else the drivers aren’t installed for your modem or USB-to-Serial adapter. Debugging drivers is outside the scope of this document, and on Windows requires inspecting the Device Manager too see if the device was recognized as pictured below but note that on newer Windows, if you are trying to Update drive to the original drivers from here: you may need to disable driver device signing which you will have to google based on your OS.

Once you have a functioning USB Serial Device, it will appear in the Chrome “Select the USB Serial Port” window. Select the correct one and click Connect. You should then see the following window.

You are now ready to start running the summit bridge by pressing “Run”. Once it is running turn on your summit timers. They should connect automatically and show in the example below when the operator turned on Summit #6 and #9.

The Summit bridge application detects the start signal when a Summit boots so if your Summits don’t appear immediately turn them off and back on until they appear or try refreshing the page as that may be required if the summits were already on when you first came to the page. Summit timers that have communicated with your computer in the last 24h should also automatically show up.


Connect all summit timers that you will use for the day. Try your very best to not connect a new summit timer halfway through the race as it will lead to less accurate times from that device as you can only synchronize a new device effectively if you have used the FIS Sync procedures. If you are using the FIS Sync procedure follow that guide and do NOT click Sync Time as that will re-sync the Summits to your computers time which would wreck your FIS synchronization. If this is a non FIS race though, you can click Sync Time to set the Summits to match your PC time wirelessly as seen below:

Note you MUST sync the summits before receiving any records. When a summit timer is turned on it starts at 00:00:00.00 and counts up. But Zone 4 uses a time-of-day-based system so by syncing the time it tells the summit the time of day so it can talk in a time-of-day-based system. The sync time for each device will show under “Sync Time”.


Once that is set up you are ready to time your race. Start entering times on the summit timers and the summit bridge will collect those times and send them to the Zone 4 web application.

For each device, the summit bridge keeps track of the last time, the last record number, and the last date/time that it has heard from the summit timer. This can help to see if you have lost connection to a summit timer or if something has gone wrong with a timer such as the radio batteries running low.

Records will show up under the “Records” section when they are on your local PC and as soon as they get synced to the web they will disappear from there. Below is an example where there is 1 time waiting to be pushed to the web so it’s status remains ‘local’ till it can be sent.

This allows you to continue to collect times if you loose your internet connection or even if your race is offline. Just keep the application running until your internet is restored and the application will then push the times to the web. You can also pause the application restart the summit bridge later to collect more times if needed. If the times do not start syncing right away, send a blank time from the summit timer to the summit bridge and this will help sync all the times.


In some browsers when a tab is in the background, the processes on that tab will be slow down or even pauses entirely by the browser. This is not ideal for an application like the Summit Bridge as that means you would stop getting times once the tab has been de-prioritized by the browser. The solution is to keep the tab visible in a separate window (having multiple monitors helps.) Some browsers have settings to not de-prioritize background tabs but from our experience this is only partially obeyed by the browsers as limited RAM often means something has to give and at some point they start throttling background tasks to keep the ‘visible’ tabs functioning. So you will have to get used to keeping the tab visible to ensure it is still working.

Note that when setting up your race in the Zone4 timing application, when settings which devices are to perform which role in 3. Device Setup it only lists device that is has received times from at least once before. So if this is the first time working with a new Summit Device #, you will have to record at least one time before you can assign that device to a role.

Updated on 2023-10-11

Was this article helpful?

Related Articles