[00:00] In this lesson, I'll demonstrate how to configure a local client fallback. Ignition clients depend on a stable connection with a gateway to function. If that connection is lost, the client will suspend operations as it attempts to reconnect. This can be a problem when clients need to monitor critical operations. With a local client fallback if the connection to a central gateway is lost, then a vision project on the machine that's running the client will be launched. This project can be set up with the minimum amount of real-time information required to keep operations running until that connection can be reestablished. I've created an environment to replicate a scenario where I have a local ignition installation on site with me and a gateway that's in a different centralized location. Both of them are also connected through the gateway network. My central gateway is the standard ignition installation and has connections to things like my database server. My local gateway is an edge installation with connections to local devices.

[01:06] It's physically separated from the central gateway, and the network connection between them isn't always reliable. An important note about this Edge gateway is that it's also installed on the same machine that I'm going to be launching clients from. When the connection to the central gateway is up, I want operators to use its project. However, when that connection goes down, I want them to still be able to continue operations at the local site with the Edge project. In order to accomplish this, I'll need to configure a local client fallback on the local gateway. I'll start by opening the Edge gateways platform tab and navigating to the gateway settings. Then I'll need to scroll down to the local vision client fallback section. I'll click this checkbox to enable local fallback, and then I need to specify the project to use during fallback. This is an edge gateway, so the default project is named Edge. This other property here controls how long the client will wait before switching to the local gateways project.

[02:04] I'm going to leave this set at the default of 60 seconds, but if you wanted to increase or decrease that, this is the place to do it. It's also important to note that Port 6501 must be open on the local machine in order to use local client fallback. Once I'm finished with these configurations, I'll click save Changes. Now I'll open up a client for the central gateway project. Under ideal conditions, operators will use this project and get access to everything the central gateway has access to. However, in the event of a network problem, which I'll trigger on my other screen, communications will drop and the project won't be accessible. Then operators will see the gateway connection loss window. This window will notify that the connection is lost. The local fallback project will be detected, and a countdown for whatever value was in the seconds before failover property we saw in the local gateway will start. Once the timer reaches zero, it will automatically switch to the fallback project. However, failover can also be triggered manually by clicking this button here.

[03:06] Now my operators can continue working in this project, which gives them just enough time to keep operations running while communications are down. After the fallback project is launched, it won't automatically transfer back to the central gateway when communications are restored. However, you can create your own functionality to accomplish this. My project monitors the status of the central gateway and displays this button when it detects its running. Clicking, this will retarget the client back to the central gateway project. To see an example of how to retarget via a client timer script, check out the user manual link in the resources below the video.