Using NI Switch Executive in NI TestStand

Using NI Switch Executive in NI TestStand, you can configure switching actions for TestStand steps. Implement individual switch operations for your TestStand steps with the Switching panel on the Step Properties dialog box. The IVI Switch step type supports not only the IVI class layer but also NI Switch Executive operations.

TestStand Switching Panel

TestStand includes a Switching panel on the Properties tab of the Step Settings pane. Use this feature with NI Switch Executive.

Use the Switching panel to specify the switching action you want TestStand to perform for a step. The following figure shows the Switching panel:

The Switching panel contains the following controls:

• Enable Switching—Specifies whether to perform the specified switching action for the step.
• Switch Executive Virtual Device—Specifies an expression that TestStand evaluates at run time to determine the virtual device on which TestStand performs the switching action.
• Operation—Specifies whether to connect or disconnect the specified routes or to disconnect all previously connected routes. This operation returns as soon as the instrument is ready for another operation, which may occur before or after the switches involved settle. Select the Wait For Debounce Before Executing Step checkbox if you want to wait until all switches have debounced. You can select from the following options:
  • Connect—Connects the paths for the specified routes in the Route(s) to Connect control.
  • Disconnect—Disconnects the paths defined by the specified routes in the Route(s) to Disconnect control.
  • Disconnect All—Disconnects all paths previously created.
  • Connect/Disconnect—Connects the paths for the routes specified in the Route(s) to Connect control and disconnects the paths for the routes specified in the Route(s) to Disconnect control. Use the Operation Order ring control to specify whether the disconnect operation occurs before or after the connect operation.
• Route(s) to Connect—Specifies the routes you are connecting. The expression must be a valid route specification string as defined by the NI Switch Executive configuration for the virtual device name you are using. The string can be a combination of route group alias names, route names, and physical route paths.
• Route(s) to Disconnect—Specifies the routes you are disconnecting. The expression must be a valid route specification string as defined by the NI Switch Executive configuration for the virtual device name you are using. The string can be a combination of route group alias names, route names, and physical route paths.
• Multiconnect Mode—Specifies the behavior when more than one connection operation occurs on a specific route. You can select from the following options:
  • Multiconnect Routes—A route can be connected multiple times. The route must contain the same endpoints and path. NI Switch Executive automatically reference counts the routes. If you issue multiple connect operations for a specific route, the route is not physically disconnected until an equal number of disconnect operations occur. You can either issue the Disconnect operation manually or use a lifetime setting for the route. The Disconnect All operation disconnects a route even if the route reference count is greater than 1.
  • No Multiconnect—A route can only be connected once. Any attempt to reconnect a route that is already connected results in an error.
  • Use Default Setting for Route—Use the setting defined for the route in the NI Switch Executive virtual device configuration.

    Note  Use Default Setting for Route was first available in NI Switch Executive 2.0.

• Operation Order—Specifies whether the Disconnect operation occurs before or after the Connect operation. You can select from the following options:
  • Disconnect Before Connect—Disconnect the specified routes before connecting any routes. Disconnect Before Connect is the typical mode of operation.
  • Connect Before Disconnect—Connect the specified routes before disconnecting any routes. Use this mode of operation when you are switching electric current and want to ensure that a load is always connected to your source.
• Connection Lifetime—Specifies the lifetime that TestStand applies to the routes specified for the connect or connect/disconnect actions. You can specify whether you want the route to exist until manually disconnected later, or until the step, sequence, thread or execution completes. If you use the Multiconnect Mode, a route can exist longer if another step specifies its own lifetime for the same route. Selecting a lifetime other than manual guarantees that the route stays connected as long as the step, sequence, thread, or execution in which you connect is still executing. If you manually disconnect a route that was previously connected using a non-manual lifetime setting, TestStand releases the reference to the route for the last step that performed a connect action for that route.
• Wait for Debounce Before Executing Step—Specifies whether the operation waits for all switches to debounce before returning to TestStand. The wait for debounce occurs after both Connect and Disconnect operations are complete.