Plots in Controller or Scope do not display data

Tech Note: TN0277
Product: OpenEx
Version: All
Date Added: 2008-02-15

Issue

Plots in OpenController or OpenScope might not display any data even though the plot appears to be configured correctly. This issue commonly arises when an RCO file assigned to inactive device in OpenWorkbench uses the same StoreID as the active RCO file.

When devices, or device configurations, are created in OpenWorkbench, the StoreIDs contained in the assigned RCO are added to a master list that is used by other OpenEx applications (such as OpenController) to retrieve data. This list of StoreIDs does not include information about which device configuration contained the StoreID, so they will remain in the list even when a device configuration is inactive (or not assigned to any hardware device).

In OpenWorkbench, multiple device configurations can be created using the same or different RCOs, any of which might include duplicate StoreIDs. Workbench will warn the user if two active devices include the same StoreIDs (see Tech Note #0271 for more information), but no error is reported when the duplicate StoreID is contained in an RCO assigned to an inactive device configuration.

In the image below, device Acq3 is currently enabled and loaded with an RCO file that contains a store with the tag name 'eNeu'. Device configurations ~Acq1 and ~Acq2 are currently disabled and are loaded with RCO files that also contain the StoreID name 'eNeu'.

Once OpenWorbench is running, duplicate instances of the eNeu StoreID will occur and client applications like OpenController may point to an inactive StoreIDs rather than the active one.

Solution

To avoid this problem, delete inactive device configurations or ensure all Stores use a unique StoreID.