Problems in getting signals from Hall Sensor through NI-9401

[Blokk]

just some spec data and general advert.

This link does not give any idea how this sensor should be connected, and what are the pin connections.

Also, we need info about what kind of signal "coming" from the sensor.

Do you have any real manual?

[LaxG]

Dear Blokk,

Thanks for the helping hand. 

At present, I do not have a detailed manuel which I can upload here, but  a person from Electronics background helped me with the connections of the sensor.

I am new to sensors, I am requesting you to kindly tell me what kind of signal output will be apt for these kinds of applications. Sorry for this.

Regards

[johnsold]

The fundamental Hall sensor generates a continuous (analog) signal, probably in the millivolt range. There are three possiblities for how the output is processed:

1. The raw Hall signal is available at the output.

2. A linearly amplified Hall signal is the output.

3. The Hall signal is amplified and then run through a comparator to produce a logic circuit compatible signal.

Of the three types only  #3 will work reliably with your Digital Input device. Even then it is possible that a pullup resistor or other external circuitry may be required. Output type 2 might work but only over a narrow range of possible parameters. Output type 1 would never work.

The link you posted gives no information and very few clues about which output type the sensor generates. That is why Blokk and I have asked for more information.

Lynn

[Blokk]

Just a guess, but I can imagine this sensor is not for general use: the company sells it as a replacement for cars, and the suitable "reader" electronics is in the car. Often in similar cases these companies do not publish detailed sensor and interface info, so other companies cannot copy their patents...

If so, you may face a pretty big challenge, reverse engineering can be very hard...

Other option is that, you purchase a sensor which is well documented, and creates a proper digital signal. And you use this sensor with your NI card...

EDIT: actually what is your goal here? You want to read out rotational engine speed info from cars? Isn't it available via the onboard car computer (or whatever it is called)? I have heard about that some companies sell interface cable so you can connect your laptop to the car and read out online diagnostic info...

[LaxG]

Dear Lynn and Blokk,

Thanks for your continous support.

I am planning to use this sensor for measuring the rotational speed of a shaft using a hall sensor in a test bench and to get the real time signal output into the LabVIEW program.

Which of these sensors do you suggest? Shall I stick to hall sensor or go for optical sensors for speed determination. I started working with hall sensors bcoz of cheaper costs involved.

Please check this link for hall sensors provided by IFM.

http://www.ifm.com/ifmgb/web/pmain/015_020_030_050_010_001.html

I am planning to go for this one

http://www.ifm.com/products/gb/ds/MX5000.htm

Regards

[Blokk]

Looks promising, but I did not find detailed info about the digital signal levels (there is a graph in the "manual" showing some square waveforms, that is all).

I would contact this German firm, and ask them about whether you can use this sensor with your NI DIO card directly?

I have found a similar sensor:

www.hallsensors.de/CYGTS211-212.pdf

they explicitely say it creates TTL signal, so I think it could also work with your NI DIO card...

[johnsold]

On the "More Information" tab of the MX5000 page it describes the electrical design as "open collector NPN." That may be fast enough on the falling edge of the signal but almost certainly will not be on the rising edge. And you must wire a pull up resistor to get it to work at all.   If you want to use that device place a Schmidt trigger inverter between the sensor output and your DIO input. 

Lynn

[LaxG]

Dear Lynn and Blokk,

I will be using a sensor from Lorenz technik. Please find the attached datasheet (in Eng and german). It has TTL signals as output.

In order to get the rotational speed, I am using NI 9215 (BNC) and have already connected the sensor. Is it the right Daq for measuring speed

I will get voltage as an output, how do I get speed signals from voltage?

Best regards,

LaxG

[Blokk]

Try to measure properly the digital signal, this is the first step.

After that, the manual should describe how to translate the digital info into speed, etc...

I did not find info about how to translate in the attached manual however. Try to find a more detailed description, or contact the supplier.

(http://www.lorenz-messtechnik.de/phplogin/login_en/html/software.php

Or maybe someone has experiance here in the forum how to deal with such sensor, I never worked with one...

But for sure, first you should get your DAQ set up and running, and by changing the rotation speed you may find out how the digital signal can be decoded into rotational speed for example.

edit1.: I am not totally sure, but it is also possible that you can just use a simple serial cable to connect this sensor to your laptop/PC (or using a usb-RS232 converter). There is also downloadable LabView driver at the website...

[JGoebel]

Dear LaxG,

i've been watching this thread for a while now, and i think its gotten kind of stuck.

Could you give me a short response, if the problem is still present?

If yes, could you post a Screenshot of the Outputsignal of the Sensor measured by an Oscilloscope, or an Analog Input?

Greetings,

Jan Göbel

Applications Engineer