Powering a hall effect speed sensor from a cDAQ chassis

[mdb1018]

Hello, I am a mechanical engineering student working on a dynamometer project. I am new to LabVeiw and don't have very much experience. I am using a load cell to measure dynamometer force output and I need to relate the force data to the rotational speed of the engine/dyno utilizing a honeywell LCZ460 hall effect speed sensor and an NI 9361 counter card. My problem is that my professor doesn't want me to use an external power supply to send power to the sensor and would prefer that I instead power the sensor from the DAQ chassis. The sensor has a voltage operating range of 4.5 to 26 VDC and I know that the NI 9361 has a 5 VDC differential output, but I'm not sure how to make this work. Any suggestions on a method to gain the necessary supply voltage for this sensor from an NI DAQ would be very much appreciated.

[santo_13]

I believe you're misinformed that the 9361 has a 5V output. The only thing it has is the Vout pin which is a loopback from Vsup that the user supplies to the module.

5V differential mentioned in the datasheet is for the input signal support and not an OUTPUT.

You could even tap wire from the DAQ chassis power supply if you're very strict about avoiding extra power supply.

[mdb1018]

So, is there a way that I can pull a supply voltage to power the hall effect sensor for the count card signal without modifying the DAQ chassis, perhaps from another DAQ card? I know I could use an output card to provide voltage, but it does not make logical sense to me to need an input card to operate an output card to supply voltage to a sensor so I can get a signal back from it.

Not using an external power supply is not my preferred method, but since I will not be the one that is going to have to operate this dynamometer when I am gone, I must conform to this method.

Thank you in advance.

[santo_13]

Yes, if the cDAQ chassis uses an external power supply, you can use the same to power your hall effect sensor.

Each c-series slot is limited in power budget and typically only sufficient for the operation of the c-series module and not much to power up external circuits. What are the cDAQ chassis and the list of modules you've?

[mdb1018]

Sorry I didn't get back to you sooner. I'm working with an NI 9361 cDAQ with an NI cDAQ-9178 chassis. I know that this card has a 5VDC pull up circuit that can supply the excitation voltage to the hall-effect sensor for the comparator to complete an edge count, but I am having trouble with getting the pull up voltage to work as there is no place in the VI DAQ assistant (LabView 2018) to tell it that you want to use the pull up circuit. Would you have any suggestions on using this pull up resistor?

Thank You,

Mike B

[santo_13]

This article explains how to enable/disable the pullup - https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000PA2cSAG&l=en-US