Publishers can be considered the opposite of data sources. Instead of gathering data into the system, publishers distribute data out. This can be useful when using DGBox to gather information from disparate systems in order to modify, cleanse, or otherwise manage it, and then send it in a common format to other systems. In this way, DGBox is not only M2M, but M2M2M. Publishers can even be used to send data to other DGBox and non-DGBox instances, perhaps consolidating data among various field instances into head-office management data. Indeed, instance of DGBox can use publishers to control each other in many ways.

The data publishing layer enables publishing of data from multiple devices through the following protocols:

Publisher List

The publisher list lists all publishers defined in the system, displaying the name, type, configuration description, and status for each. Configuration depend on the publisher type. The Status determines whether the publisher is enabled () or disabled (). Clicking on the status icon toggles the publisher's status.

To add a new publisher select the publisher type from the list and click the icon at the top of the list. To edit an existing publisher, click the icon associated with the publisher. To delete a publisher, click the icon associated with the publisher.

Common Publisher Configuration

Every publisher has a Name which is used to visually identify it in lists. It is recommended that each publisher have a unique name, but is not required. The Enabled checkbox is used to enable or disabled the publisher.

Publishers use caches to ensure that every point update is delivered to its destination. If the destination for whatever reason does not accept these deliveries for an extended period of time, this cache can become very large. A Cache warning size can be defined which causes an alarm to be raised whenever this queue size is exceeded. This alarm returns to normal when the cache is less that 90% of this warning size, or when the publisher is disabled. To prevent memory problems, publishers also define a Cache discard size. If the queue size is found to exceed this value entries will be discarded until the queue is again at an acceptable level. Entries in the queue are also discarded when the publisher is disabled.

The Update event value determines whether all point updates are delivered, or only point changes.