Keysight Technologies M9010A User Manual

Also see for M9010A PXIe: Troubleshooting guide Security guide Service guide Reference guide

Contents

Keysight Technologies M9010A User Manual Manual pdf 67 page image

Keysight PXIe Chassis Family User Guide 67Monitoring Chassis Fan Speeds Chassis Cooling and Rack MountingMonitoring Chassis Fan SpeedsBoth the M9018B and M9019A chassis contains three fans that are mounted onthe chassis rear panel and provide cooling for the chassis; the M9010A chassishas two fans. The chassis allows you to monitor the speed of each fan inrevolutions per minute (RPM). You can also set a minimum fan speed thresholdsuch that, if any fan speed falls below this threshold, a fan speed alarm isgenerated.These monitoring capabilities are available using the Soft Front Panel (SFP) andprogrammatically using the chassis drivers. In addition, the front panel Fan LEDprovides information on fan speeds. Use of the SFP, the front panel Fan LED, andthe IVI drivers to monitor the chassis temperature sensors are described in thefollowing SFP and the front panel Fan LED diagram.Setting the Fan Speed vs. Chassis Temperature ProfileThe chassis allows you to control the fan speed vs. temperature profile. This isdone by specifying a chassis temperature at which the three fans will operate atmaximum speed. Maximum speed is achieved by the chassis supplying a drivevoltage to the fans with a 100% duty cycle.For temperatures below the specified chassis temperature, the duty cycle of thefan drive voltage will be less than 100%, which reduces the fan speed and thefan noise. The reduction in fan speed is proportional to how far the chassistemperature is below the specified chassis temperature. To ensure adequatecooling at any temperature, the drive voltage to the fan will never drop below40% duty cycle.These fan speed vs. chassis temperature profile can be set using both the SFPand programmatically, as described in the following diagramDefault Minimum Fan Speed Threshold LimitThe M9010A has a default minimum fan speed limit of 900 RPM. The M9018Band M9019A have a default minimum fan speed limit of 1200 RPM. These defaultlimits are applied on chassis power on. The following diagrams apply to bothtypes of chassis, but the examples show the default minimum fan speed of 1200RPM for the M9018B and M9019A.