Maximum Allowable Cable Length for NI PXIe-4139 SMU

Updated Nov 14, 2023

Reported In


  • PXIe-4139
  • PXIe-4138

Issue Details

  • I have PXIe-4139 SMU and would like to know how long wires I can use to connect the SMU to my DUT?
  • Between my DUT and my PXI system, there is about 30 to 50 meters. I saw documents regarding load considerations, for example about capacitive loads. Is there any nuances regarding cable length?


We need to take into account electromagnetic compatibility (EMC) guidelines for NI PXIe-4138/4139.

This products were tested and complies with the regulatory requirements and limits for EMC stated in the product specifications. These requirements and limits provide reasonable protection against harmful interference when the product is operated in the intended operational electromagnetic environment.

As indicated in the getting started guide for the PXIe-4138 or PXIe-4139, the maximum allowable cable length is 3 m (10 ft).

Additional Information

This products are intended for use in industrial locations. However, harmful interference may occur in some installations, when the product is connected to a peripheral device or test object, or if the product is used in residential or commercial areas. To minimize interference with radio and television reception and prevent unacceptable performance degradation, install and use this product in strict accordance with the instructions in the product documentation.