NI sells CAN cables
of 1m and 2m length.
If you need longer cables for your application, confirm with the NI product documentation for your device, the XNET Manual, and/or the SAE J2411 or ISO 11898, CiA DS 102, and DeviceNet specifications. You may need to create your own cable or purchase from a third party. NI cannot guarantee your application will work outside of the cables NI sells.
Specific information for Cable Length and Requirements for a NI product can be found the Getting Started Guide and/or User Manual of the specific product. For example, for the NI 9862, the Getting Started Guide has a section for Cabling Requirements for the NI 9862