When a Generic Modbus Direct or Shared controller is first added to a ClearSCADA system and you associate that controller with a Advanced Modbus Direct Channel, the state of the controller will initially register as ‘Healthy’ and the state of the channel will remain as ‘Disconnected’. This initial Generic Modbus controller state is not a true indication of that controller’s status. It is only once you have added point(s) to the controller and ClearSCADA polls that controller for point data via the channel, that both the controller’s and channel’s states update to indicate their true state. (If ClearSCADA polls the controller successfully, that controller’s state will remain Healthy and the channel’s state will also update to Healthy.)
In situations where a Generic Modbus Direct or Shared controller remains without any associated points in the ClearSCADA database, the state of the controller will remain as ‘Healthy’ although this will not be a true indication of that controller’s status. (Generic Modbus controllers do not universally support a start comms message that ClearSCADA can use to ascertain the correct state of such a controller until it has polled that controller for point data.) Similarly, the Advanced Modbus Direct Channel that is associated with such a controller will continue to show a ‘Disconnected’ state until ClearSCADA polls that channel for point data (on either that controller or any other controller that uses that channel).
Further Information
Ascertain the State of a Controller or Channel: see Monitoring the State of Direct Communications on your System in the ClearSCADA Guide to Advanced Drivers.