NI 9862 External Power Supply

[Nana2323]

Hi everyone,

I'm quite new to working with National Instruments (NI) modules and I'm currently stuck on the first step of setting up the NI 9862 for a registration task. The instructions mention that the NI 9862 requires an external power supply, and I'm wondering if this means that the power supply from the cDAQ-9174 chassis is not enough.

Has anyone here used the NI 9862 with the cDAQ-9174 chassis? How do I connect the external power supply to the NI 9862 module? Do I need to power the module separately, or will the cDAQ-9174 provide enough power once everything is connected?

I’d appreciate any guidance or tips!

Thanks in advance!

[rolfk]

The CAN side is completely galvanically isolated from the backplane. This means that there needs to be a power supply on the CAN side too to let it work. While it would be a possibility to have included a DC-DC converter in the module to provide such a power supply there are many reason why not to do that.

It's a considerable cost factor to integrate such a converter in a module.

It's additional hardware that can get damaged (rather easily if you connect the CAN connector wrong).

The power supply implemented by NI in the module could potentially have to be fairly beefy depending on what is connected through the CAN bus.

In most industrial situations there is an actual power supply for the hardware connected through the CAN interface, so why complicate the setup (and increase costs) with yet an other component?

If the external hardware doesn't have its own (accessible) power supply, you can use a fairly cheap net plugin adapter anyways that costs a few 10$ at most. If it was integrated in the module it would make the module several 100$ more expensive, also for the many customers not needing such a power supply since the power supply for the ECU or whatever is available anyways.

[ZYOng]

Connect a 9-30V to pins 9 and 3 of CAN connector. See High-Speed CAN Pinout

If you don't want to make your own cable, you can buy CAN cable with power terminals from NI. See shop NI CAN cables