PXIe-1071 auto fan speed not working properly

[7maxmustermann7]

Hello,

I use the PXIe-1071 in a office. The fan speed switch is in the "auto" position.

After power on the system, the fan speed is maximum and remains at its maximum. After the switch is manually switched to "max" and then back to "auto", the speed is reduced. Normally the fan should run at maximum for a short time and then run immediately at a reduced speed. The temperatur of the system was low, approx 25°C.

[hovo90]

Hi,

Could you please describe the setup in detail?

What SW is install?

Best Regards.

[7maxmustermann7]

The System is:

- PXIe-1071 Chassis (Firmware 1.0.0f0, Hardwareversion F)

- PXIe-8821 Controller (Firmware 2.0.2f0,Hardwareversion A, Win10 Enterprise)

- PXI-4130 SMU (Firmware 8.8.18f15, Hardwareversion E)

- PXIe-4080 DMM (?, Hardwareversion B)

There runs no special software, the system is nearly in condition as delivered.

Best regards.

[hovo90]

Hi,

As the first step of troubleshooting, I would suggest removing all modules from the chassis and left inserted only the controller.

If the issue is solved, then start inserting modules one-by-one, in order to figure out which module causes the issue.

Regards.

[7maxmustermann7]

Hello,

I removed all modules but the fan remains at maximum speed all the time...

Is the speed behavior controllable by software or BIOS?

Best regards.

[toddy]

I believe the speed in AUTO mode is controlled based on the temperature sensor which is on the inlet to the fan. It's really not very useful, as the mesh filters got blocked quite quickly and only a small amount of lint/fluff on them reduces the flow to almost nothing. The temperature sensor has no idea that the interior of the chassis is then getting hot, so doesn't do anything about it.

We were advised for this reason that we shouldn't run the systems with it in AUTO mode. The trouble is the alternative is ridiculously loud, so we do still run in AUTO, but I clean the mesh filters regularly (once every 3 months in our office).

It doesn't help with your particular problem. I would add though that I don't think it's related to any software on the controller, I think it is managed entirely by the chassis.

[7maxmustermann7]

Hello,

thank your vor the advice, I will keep in mind. I couldn't solve the problem and so I send the chassis to NI for repair.

Best regards.