Issue
Is it possible for multiple Automation Servers to be placed on the same backplane and use one power supply?
Some known issues in this unsupported configuration:
- Automation Server only partially discovers the IO Modules
- Function Block Programs (FBP) remain in an unloaded state (see FBP Unloaded)
- EBO 2022 (v4.0) and higher, Alarm: IO Driver unexpectedly timed out
Product Line
EcoStruxure Building Operation
Environment
- EcoStruxure Building Operation Automation Server (EBO 2022 and above)
- EcoStruxure Building Operation Power Supply (PS-24V)
- EcoStruxure Building Central IO Modules
Cause
The terminal bases provide a path for communication between all connected units on the same backplane; as such, the connection of two or more Automation Servers will cause communication issues between all connected units on that same backplane.
See the following article on how to check the CIO node the Automation Server is using: How to identify Automation Server(AS) ID node count
Resolution
From EBO 2022 (v4.0.1) due to changes in the Central I/O (CIO), checks are now made in the Automation Server to verify that the server is physically in SLOT 2; if this is not the case, then all Tasks are disabled and will not run.
You cannot connect more than one Automation Server to the backplane. Only one Automation Server is allowed per power supply, the architecture is always "PS-AS-....." and after that I/O modules with additional PS units as needed, but only one Automation Server can exist on the same backplane.
Note that an alarm will also generate if you attempt the following configuration (also not supported)
- PS-AS-PS-AS
Alarms will only clear after a restart (warm) of the server
