Small system on BACnet/IP

Small system on BACnet/LonTalk

Medium system

Large system

PX site

PX site is a means of structuring large PX projects. Desigo room automation stations are not part of a PX site.

In a PX site one PX automation station is defined as the primary server and all other PX automation stations are defined as backup servers. Every automation station can be defined as the primary server.

The primary server carries out system functions, such as time synchronization, life check and the distribution of global data:

  • Time synchronization: The primary server distributes the current time to the backup devices.
  • Life check: The backup servers detect the failure of the primary server and the primary server detects the failure of the backup servers. If a server fails, an alarm message is sent. If the primary server fails, another automation station must be defined manually as the primary server.
  • Distribution of global data: Global objects are available on all PX automation stations. The primary server synchronizes changes, e.g., calendar object, notification class object, that are made on the primary server to the backup servers.

Handling a PX Site in Desigo clients

When an operating device starts, it searches for all primary servers and offers a log in to the PX site.

A Desigo CC site can contain several PX sites and third-party devices. Desigo CC registers itself as a global alarm recipient for the PX site on the primary server.