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Is the roboRIO DIO Compatable with the AB Line Sensor?

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I was looking at the Allen Bradley 42EF-D2MPAK-F4 found in the KOP.

Here is a link 

 

According to the pdf the supply voltage is 10-30vdc and it is a PNP type which means it delivers supply voltage to the outputs.

AB Sheet.png

The specification on the roboRIO does not give a max input voltage for the digital inputs.

Can the roboRIO's DIO handle a 12VDC input.

 

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Hello Mark,

 

The roboRIO's DIO is designed to work with 5 VDC TTL levels, and I wouldn't expect it to work nicely with 12 VDC as an input.

 

I also read in page 4 of the Specification Sheet you mention:

Digital I/O

 Input logic levels

  Input low voltage = VIL 0.0 V min; 0.8 V max

  Input high voltage = VIH 2.0 V min; 5.25 V max

 

It says to me not to feed more than 5.25 VDC, do you interpret it in a different way?

 

Good luck to your teams with Destination: Deep Space!

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I assumed something different when I read it last time but going back over it I agree with you that 5.25 may be the max voltage you can input into the DIO signal pin. 

 

That data tells me the logic level will be high from 2.0 to 5.25  but I did not interrupt that as anything above 5.25 would damage the input.

 

Many time a datasheet will post an absolute max value and that is what I was looking for.

Can you check with the hardware people about the absolute maximum of the DIO?

 

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Any update on this issue.

 

I need to know if I need to order 5v zener diodes or if the roboRIO can handle a 12VDC input.

 

Thanks

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Spec sais max of 5.25V - http://www.ni.com/pdf/manuals/374661a.pdf#page=3

 

You might want to consider a logic level shifter instead of Zener diodes like this one: https://www.sparkfun.com/products/12009 (rated for up to 60V)

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The link that you provided is for a 5VDC to 3.3VDC converter.

For the AB sensor we will need a 12VDC to 5VDC converter.

Someone on CD found these Voltage Detectors.

https://www.amazon.com/gp/product/B06XHKZCD4/ref=ppx_yo_dt_b_asin_title_o00__o00_s00?ie=UTF8&psc=1

 

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@MarkBalla wrote:

The link that you provided is for a 5VDC to 3.3VDC converter.

For the AB sensor we will need a 12VDC to 5VDC converter.

Someone on CD found these Voltage Detectors.

https://www.amazon.com/gp/product/B06XHKZCD4/ref=ppx_yo_dt_b_asin_title_o00__o00_s00?ie=UTF8&psc=1

 


It is marketed for stepping 3.3v up to 5v, but it is a standard bi-directional shifter (schematic). If you put 12V as the high and 5v as the low, it will step down the voltage (demo using a slightly different model of same type of transistor). And the datasheet for the transistor used (linked from product page) says the max in for the transistor is 60V.

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Hi,

 

Thanks for posting this circuit diagram! I am looking into using this exact sensor and want to make sure I don't fry our Roborio. This Sparkfun board looks like it would do just the trick to step down the voltage of the photelectirc sensor to 5V. What I was wondering is how this sensor would be connected to the robot. The power and ground of the sensor would go to the VRM I assume as it can output 12 V. Would the data out (Either dark or light) pass through the Sparkfun board and then into the DIO of the Rio?

 

How would the digital out be connected to the logic level converter? Is it as simple as connecting the sensor out to the 'HV' pin and then connect the 'LV' pin to the rio?

 

Thanks

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@mjshafer93 wrote:

 


@MarkBalla wrote:

The link that you provided is for a 5VDC to 3.3VDC converter.

For the AB sensor we will need a 12VDC to 5VDC converter.

Someone on CD found these Voltage Detectors.

https://www.amazon.com/gp/product/B06XHKZCD4/ref=ppx_yo_dt_b_asin_title_o00__o00_s00?ie=UTF8&psc=1

 


It is marketed for stepping 3.3v up to 5v, but it is a standard bi-directional shifter (schematic). If you put 12V as the high and 5v as the low, it will step down the voltage (demo using a slightly different model of same type of transistor). And the datasheet for the transistor used (linked from product page) says the max in for the transistor is 60V.



Hi,

 Thanks for posting this circuit diagram! I am looking into using this exact sensor and want to make sure I don't fry our Roborio. This Sparkfun board looks like it would do just the trick to step down the voltage of the photoelectric sensor to 5V. What I was wondering is how this sensor would be connected to the robot. The power and ground of the sensor would go to the VRM I assume as it can output 12 V. Would the data out (Either dark or light) pass through the Sparkfun board and then into the DIO of the Rio?

 

How would the digital out be connected to the logic level converter? Is it as simple as connecting the sensor out to the 'HV' pin and then connect the 'LV' pin to the rio?

 

Thanks

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The power and ground of the sensor would go to the VRM I assume as it can output 12 V. Would the data out (Either dark or light) pass through the Sparkfun board and then into the DIO of the Rio?

 

How would the digital out be connected to the logic level converter? Is it as simple as connecting the sensor out to the 'HV' pin and then connect the 'LV' pin to the rio?

 

Thanks



Hi,

You can get the 12V from either the VRM or the PDP, I would probably do the VRM since it will be going though a 10K resistor (so pulling less than 1 mA) and you want this to be along with the last things to fail in the case of brown out (as opposed to hooking it to the PDP where it will be among the first).

Yes, the signal from the sensor would "pass" through the level converter. Hook the sensor up to an HV and the desired signal pin on the DIO port of the roboRIO to the corresponding LV pin. (you can get the 5V and ground for that side from the DIO pins or the VRM).

 

I'm attaching a diagram in case I'm not explaining very well.

Capture.PNG

 

 

 

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