A proxy server may be needed when a stream of data needs forwarded through an intermediate level in the network, such as in the Purdue Model shown below where there is no direct path from Level 3 to Level 4.

The proxy consists of a Receiver and Sender service. The Receiver service accepts incoming data streams from other Collector/Sender's and places them back in the local Sender to be forwarded on to other Receiver/Historian's. Using a local Sender service, the proxy has the ability to log the data to a local historian and/or multiple remote historians.

The proxy is primarily a Receiver configuration, inasmuch, any Receiver has the potential of also becoming a proxy to forward data onward.

Configuration

The following configuration is solely for a proxy set up. It is possible that other services may need installed if wishing to utilize more Canary services on the same machine. At a minimum though, the proxy will need the Sender and Receiver service.

1. Run the Canary System Installer and select the 'Store & Forward' checkbox. This will install the Canary Admin Service, Sender, Receiver, and Canary Admin Client.
2. Once installed, open the C:\Program Files\Canary\Receiver\proxy.config file.
3. Set <proxyEnabled> to "true" then add/remove/edit the <historian> parameters. If wishing to log data to a local historian, use 'localhost'. Any number of additional historians can be added to the file.
4. Restart the Receiver service. A service restart is needed any time changes are made to the proxy.config file.