Multisite Programming with Switches

In test layouts where users need to share an instrument channel between multiple DUTs, an instrument channel between multiple pins on the same DUT, or multiple instrument channels on a single DUT pin, a switch can be used to properly route instrument channels to DUT pins.

When you must share a channel between the same DUT pin on multiple sites, use a switch to control which pin the device is connected to when executing a test. Some examples of this type of multisite layout are shown in the following figure.


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Switches can also be used to share a single test resource between multiple channels or pins within a single subsystem. A subsystem is a part of the test system which can operate independently. The following figure shows a switching architecture for sharing a single instrument channel between multiple DUT pins on a single site.


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The following figure shows a switching architecture for sharing a single DUT pin between multiple instrument channels with different instrument types within a single subsystem.


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Switch Executive connections in the Pin Map Editor can be used to build the connections between instrument channels and a pin on a site. However, the ECU Action or ECU Multi Test step doesn't know which instrument type you are using, so it may miscalculate the number of subsystems. To address this, you need to define virtual pins to build the connections between these instrument channels. Virtual pins are pins which do not physically exist, but that can be created in the pin map for the purpose of mapping two instrument channels to a single physical pin.

In this example, Pin A is undergoing both a pin impedance test executed by an SMU device and a signal frequency test executed by a Scope device. To capture these tests correctly in the Pin Map Editor, you must follow one of two procedures:
  • To physically define the connection between Pin A and one instrument,
    1. Define Pin A in the Pin Map Editor.
    2. Define Pin A's connection to one instrument, such as the Scope device.
    3. Define a virtual pin, such as SMU_A, to build the connection between the SMU device and Pin A.
  • To define all of Pin A's connections using virtual pins,
    1. Define two virtual pins, such as Scope_A and SMU_A, to build the connections between Pin A and the Scope and SMU channels through a Matrix device.