The Device Mesh

The device mesh is used by tills running the Paimnt Till App (rather than the web pos in a browser) to share sales and table information between each other. Its main purpose is to share table and tab sales, and protect against multiple tills attempting to access the same table simultaneously in a hospitality environment without requiring a dedicated table server or a completely uninterrupted internet connection. In addition, it can allow looking up transactions and reprinting tax invoices done on another till and protect against loss of sales if a device breaks when not connected to the internet, even if no tables are in use.

How Tills Connect#

All tills with will maintain a connection to the Nexus that stores your database as long as they have an internet connection. This connection is how the tills send sales information back to your database and receive all the information about products, keyboards, settings and anything that they need to operate.

In addition to this, each till running in the Till App will attempt to connection to other tills on the same network to form a mesh. This allows them to share some information even if the internet is down.

How Tills Form a Mesh#

When the till app starts up, it will search the network for other tills. By default, it will try to connect to 3 other tills, which are call its peers (the number of peers per till can be changed in the Till Configuration Settings). These 3 tills will be connected to other tills so that even in large venues, the tills should all be connected directly or through other tills. When a till makes a change to a sale it will pass this change to its peers, which will pass it on until all the tills receive the change. This means that all tills will quickly have up to date information for tables and sales done on other tills, allowing other tills to use tables that have been opened on other tills and even reprint the receipt for a sale done on another till if necessary.

How Tables Use the Mesh#

When tables and tabs are in use, the mesh also helps protect against more than 1 till making a sale to a single a la carte table or tab at the same time. This is done by assigning a till as the owner of a table or tab. Generally the owner of a table is the last till to have opened and used the table. If you want to open and use the table on another till, that new till will check that the till that currently owns the table is finished with it, and then will become the new owner. This way, you should never be able to open a table until the last till to open the table has properly saved the table and no longer has it open.

When using a tab, the ownership applies to all tables and sales that are linked to the tab.

So, what happens if the owner of a table is no longer on or connected to the network? How do we know which till owns a table?

The Mesh Viewer#

The mesh viewer window in the till app allows us to see which tills are connected to the current till as peers, and which till owns each table or tab.

This can be opened in the left side bar by selecting ‘Mesh Status’ or by pressing on the mesh icon in the top right. The number next to the mesh icon will display the number of peers the till is currently directly connected to.

The Mesh icon:

The Mesh Status Function:

The Mesh Viewer Window#

The Mesh Viewer window has 3 separate pages.

The Device and Peer Page#

1. The till ID and IP address of the till you are currently using.
2. The page selector. Press on the page you want to view.
3. A list of peers for the current till.
4. The other known tills and their peers.
5. A button that will make the current till the owner of all tables. READ BEFORE USING
6. A button that will make the current till the owner of all tabs. READ BEFORE USING

The Table Ownership Page#

1. The till ID and IP address of the till you are currently using.
2. The page selector. Press on the page you want to view.
3. A list of tables and which till owns each table.
4. An indicator that the owner of this table can’t be currently contacted. Press this to make the current till the owner of this table. READ BEFORE USING
5. A button that will make the current till the owner of all tables. READ BEFORE USING
6. A button that will make the current till the owner of all tabs. READ BEFORE USING

If you are unable to open a particular table, you can look up the table in the mesh table list to see which till owns the table. If the current till can’t communicate with the owner till, the owner till ID will display in red with an arrow icon (see label 5 in the image above). To gain access to this table again, you can follow the steps in the FAQ How do I access a table that just displays “Awaiting $$$response?”.

The Tab Ownership Page#

1. The till ID and IP address of the till you are currently using.
2. The page selector. Press on the page you want to view.
3. A list of tabs and which till owns each tab.
4. An indicator that the owner of this tab can’t be currently contacted. Press this to make the current till the owner of this tab. READ BEFORE USING
5. A button that will make the current till the owner of all tables. READ BEFORE USING
6. A button that will make the current till the owner of all tabs. READ BEFORE USING

If you are unable to open a particular tab, you can look up the tab in the mesh tab list to see which till owns the tab. If the current till can’t communication with the owner till, the owner till ID will display in red with an arrow icon (see label 5 in the image above). To gain access to this tab again, you can follow the steps in the FAQ How do I access a table that just displays “Awaiting $$$response?”.

Manually Taking Ownership of a Table#

If a till is out of action but still owns tables in the mesh table ownership list, you can manually claim ownership of these tables on another till.

Claiming ownership of a table is done through the mesh viewer window.

To claim ownership of a single table, you can find the table in the mesh table ownership list and press the red arrow next to the current owner. This is only available if the till you are using is unable to contact the owner till.

To claim ownership of all tables in the list, use the ‘claim all tables’ button in the bottom left of the mesh viewer window.

Give Me the Short Version?#

• Tills connect directly to a small number of other tills (default is 3. This can be changed in the settings) to from a device mesh. They use this mesh to share transaction details between each other.
• You can see sales from other tills in the review sales screen if the tills are connected through the mesh.
• The mesh is used to share a la carte table information between tills.
• You can only open an a la carte table on a single till at one time. This is enforced by assigning the last till to access a table as the owner of the table.
  • A till that wants to open a table checks with the owner of that table to make sure it is no longer in use. If it can’t communicate with the owner, it will not be able to open that table.
  • You can see which till currently owns a table through the mesh viewer window and manually claim ownership of a table if necessary. Manually claiming ownership of a table should only by done when the owner till is out of action and can’t be connected back to the mesh

Best Practices#

• Avoid forcibly ending the app using the task manager or closing the window in Windows, or clearing the app in recent tasks in Android.

  • Whenever possible, use the shutdown function in the left navigation bar in the app to close the app. This will make sure all sales are synced with the Nexus database and will release ownership of any tables owned by the till.

    
• Avoid putting the till device to sleep. When it is in sleep mode it is not able to keep up to date with the mesh or pass on updates between peers.
• If restarting a till or waking it from sleep mode, avoid opening a table immediately whenever possible. If you wait at least 30 seconds before opening a table, the till should have time to connect to the mesh and get updated table information.
• If the local network is down or if using multiple tills that are currently unable to connect to a network, do not manually claim ownership of all tables or use the same table number on multiple tills. You will be able to open the table on both tills due to overriding the ownership of the table, but the tills will not be able to share table sales data and will end up with a different version of the table on each till.

Troubleshooting the Mesh#

If a till is having issues opening tables, check the mesh status in the mesh viewer window.

• If the till is showing that it has no peers, check that the device is connected to the network.
  • If the device connects with Wifi, make sure the wifi is on and the network is connected.
  • If the device is connected with a cable, make sure the cable is fully seated on both ends and that it is plugged into a live port.
  • Make sure it is on the same version of the Paimnt app as the other tills.

If the till is connected to the network and is on the same version but can’t communicate with one or more peers:

• Use the shutdown function in the left navigation bar to shutdown the app.

• Wait 30 seconds and restart the app.
• After the app starts, within 30 seconds it should connect to some peers.
• If it still can’t connect to 1 particular other till, you may need to do this on both tills.