NI-Switch Error -1074118644 Occurs When DAQmx Name and VISA Alias Are the Same Hardware: Switches
Problem: I have configured my DAQmx-supported NI switch such that the DAQmx name is the same as the device's VISA alias. When I attempt to initialize my switch with a valid topology using niSwitch Initialize with Topology VI or the niSwitch_InitWithTopology function, error -1074118644 occurs: No legacy device supports the specified topology. Use a different topology, or configure the device under DAQmx and use the DAQmx resource descriptor. Why I am receiving this error and how can I fix it? Solution: Cause To establish a session with the correct switch module, you must pass a resource name to the niSwitch Initialize With Topology VI or the niSwitch_InitWithTopology function. The syntax of the resource name depends on where in MAX you configured your switch module — under NI-DAQmx Devices, Traditional NI-DAQ (Legacy) Devices, or PXI System. Due to the in which order the database is searched for device names, the DAQmx device name, i.e. Dev1 or PXI1Slot2, is first found in the VISA Resource Descriptor data. Once a match for the resource name is found the search is discontinued; the NI-SWITCH API will not continue to search to check for multiple matches. The DAQmx device is then incorrectly identified under the category of a PXI System device. This category of device is meant to be used with legacy PXI modules, and is why the Initialize function returns with error -1074118644. Solution It is recommended that you do not use the same DAQmx device name and VISA alias for a switch device. However, if your application requires this then you can use the NI-DAQmx API rather than the NI-SWITCH API to program your switch. Related Links:
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Report Date: 12/21/2007 Last Updated: 02/06/2008 Document ID: 4GKE2U9S |
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