You can use several tablets in the same location: a register at the counter, a kitchen screen, a waiter with their own tablet. They all connect to each other over the location’s Wi-Fi and do not need internet to sync.
How they work
- All tablets are equals: there is no “main” one. Each one keeps all the data of the location.
- If one is turned off, the others keep selling.
- Each tablet has its own shift and its own cash drawer. Reports do add up the sales of all of them.
Before you start
The tablets must be on the same Wi-Fi and run the same app version. If you need to update, do it on all of them at once (see Install and update).
Join another tablet to the location
You need an employee with the Settings permission on the register that already has the business.
On the register that already has the business:
- Go to Settings > Location and devices > Devices of the business.
- Tap Add device. A 6-digit code appears, along with this register’s address (IP and port).
- Leave that screen open. The code is valid for 5 minutes and can be used once.
On the new tablet (freshly installed):
- On “What is this tablet for?” choose Join an existing business.
- Pick the register under Business registers found. If it does not appear, type the IP and port by hand.
- Type the code and tap Join.
- Wait for Copying the business data to finish; you will see “N of M records”. Until it finishes, the tablet cannot be used. If the connection drops, the copy resumes where it stopped.
- Choose the device’s role (see below).
The tablet that joins does not ask for a food.yammbo.com account: it uses the link of the register it joined.
If the tablet is not connected to any Wi-Fi you will see: “This register is not connected to Wi-Fi. Connect both tablets to the same Wi-Fi network of the shop.” (the app shows it in Spanish or English depending on its language setting).
If the new tablet already has data
A tablet that already has employees, sales or events of its own is not merged with another location. The app offers Erase this device and join, which asks for the PIN of this register’s owner and typing BORRAR. It cannot be undone: the data of two registers is never mixed.
If you tap Cancel and erase halfway through the copy, what was already copied is erased and the tablet is left like new.
Role of each device
When you join you are asked “What is this device for?”. You can change it later in Settings > Location and devices > What this device is for.
| Role | What it is for |
|---|---|
| Register | All staff. Sells and charges. |
| Kitchen or bar | Kitchen screen. You choose the Stations of this device. It can enable Enter without a PIN (only for a role that sees nothing but the kitchen) and Print orders that arrive from other devices. |
| Waiter | Opens the table map with the Mine filter. |
The same screen has Test order sound and Allow order alerts (the Android 13+ notification permission).
More about the kitchen in Kitchen.
What is shared and what is not
Shared across all tablets:
- Menu (categories, products, modifiers, stations and combos).
- Tables, roles, employees and customers.
- Sales, lines, payments, cash movements and shifts.
- Most settings: taxes, currency, service charge, payment methods, customer display message and auto-lock.
- Product photos and logo (they arrive after the data).
Stays on each tablet only:
- The device prefix and the next receipt number.
- Printers.
- The device role, its stations, “Enter without a PIN” and printing of tickets from other devices.
- The theme, the kitchen sound and the keypad lock.
- Paired customer displays.
- The keys of the link/QR payment providers (you must type them in every register that charges this way).
Check the status of each tablet
In Settings > Location and devices > Devices of the business, each tablet shows:
- “Connected now”, or “Offline. Last seen: (name)” / “Offline. Has not connected yet”.
- Its receipt prefix (“Receipts: T02”).
- “Pending to copy: N records”.
- Its role: Register, Waiter or Kitchen or bar.
- This register marks the tablet you are on.
Keeping the tablets connected
While other registers or a customer display are connected, the app shows a permanent notification (“Syncing with N devices…”) and keeps Wi-Fi on. Some brands close apps when the screen is off:
- On Samsung: Settings, Battery, Background usage limits, and leave the app unrestricted.
- On Xiaomi: Battery saver, “No restrictions”, and turn on autostart.
The card offers the buttons Allow the notice, Open notification settings and Open battery settings.
Network security
Data travels over the location’s Wi-Fi unencrypted (each tablet identifies itself with its own keys). It is a good idea to use a staff network separate from the guest one.
Conflicts between registers
If two tablets change the same thing while they are not connected, the app does not fix it by itself. You will see “There is 1 conflict between registers to review.” (or “There are N conflicts…”). People with the Settings or Reports permission can see it.
- Go to Devices of the business and tap Conflicts between registers, or Check now.
- Read each case, fix what is needed and tap Mark as reviewed.
| Case | What the app says and what to do |
|---|---|
| Double charge | ”Account X was charged Y. Check and refund one of the charges.” |
| Charge versus void | One register charged and another voided. Decide which one stands and fix the other register. |
| Change after payment | The account was already paid, but its products changed afterwards. Check that what was charged matches what was served. |
| Table with two accounts | ”Merge the accounts or move one to another table.” Use Merge tabs or Move. |
| Duplicate phone | Several active customers share a phone number. Keep only one or fix the number. |
| Duplicate barcode | Each product needs a different barcode. |
| Duplicate PIN | Two employees have the same PIN and nobody can sign in with it. Change one of them. |
| No owner | No active employee can open Settings. Give someone the Owner role. |
| Repeated prefix | Two registers use the same receipt prefix. One changes it by itself within seconds; if it stays the same, check Devices of the business. |
Merge tabs moves the products of the newer accounts into the oldest one and cannot be undone. If the accounts have discounts, the app warns that they will be lost when merging.
If you open an account that another tablet already charged or voided, the register drops it and says “This tab was paid (or voided) on another device.”
Clock out of sync
If another tablet’s time differs by more than 120 seconds, the owner sees “The time on T02 differs by N min…”. Fix it in that tablet’s Android settings; it affects, for example, ticket printing.
Remove a device
- In Devices of the business tap Remove next to the tablet.
- Confirm in Remove device. That tablet will stop receiving and sending location data and will not be able to reconnect. A tablet cannot remove itself.
The removed tablet shows “This device was removed from the business”. From there you can:
- Export unsynced sales: creates two CSV files (tickets and payments) and asks for the owner PIN. Use it before erasing if there are sales that no other register has copied.
- Erase data: asks for the owner PIN and typing BORRAR; leaves the tablet like a fresh install.
Same version on all of them
With different versions, tablets reject each other. Their data is not touched and each one can keep selling on its own; once all are updated, they reconcile.
- When joining a tablet you will see: “The other register runs another version of the app. Update both to the same version.”
- A tablet that is already joined but runs another version only shows “Offline…” in Devices of the business, without mentioning the version. If a tablet shows offline for no apparent reason, compare the versions in Settings (at the bottom of the list).
- If a tablet is on a very old version you will see: “This tablet runs an older version and cannot sync: remove it from the business and join it again (Join an existing business).”