The Reliability of all modules reflects the Reliability of its Outputs. If any Output Reliability is not reliable, then the module Reliability must not be reliable.
During Commissioning, the Cooling Tower Selector module checks the value of the Device nn Capacity and Rated Current/Power properties of all devices with indexes less than or equal to Number of Devices. If any of the required values is less than or equal to zero, the reliability of the module is Unreliable: Invalid Configuration, and the module does not execute.
If you attempt to change the Device nn Capacity to an invalid value, the module rejects the write and sends a corresponding write error.