Author Topic: AnIn used as 24vdc DigIn  (Read 3826 times)

Offline Lukey

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AnIn used as 24vdc DigIn
« on: February 15, 2024, 02:52:39 AM »
I'm trying to use the smallest size possible controller, therefor id like to use a 5v AnIn pin as a DigIn with 24vdc input. from the switch

Is it as simple as using a resistor to drop the 24vdc down to 5vdc?

Anyone done this before and can advise what size resistor they use?

*EDIT FYI, I do not want to use the 5+ from the controller or use a relay to switch the 5+.
The application requires it to be compact and simple.
« Last Edit: February 15, 2024, 02:57:01 AM by Lukey »

Offline acmall

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Re: AnIn used as 24vdc DigIn
« Reply #1 on: February 15, 2024, 09:19:02 AM »
Which controller are you using? Which input pin?

It would be worth checking the ratings for the input you are using as there is a good possibility it will be rated to more the 24V. This can be found in the Controller Family Technical Information document for the controller family you are using.

Offline Lukey

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Re: AnIn used as 24vdc DigIn
« Reply #2 on: February 15, 2024, 10:11:40 AM »
11130915 / MC012-110, pin 5

Offline acmall

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Re: AnIn used as 24vdc DigIn
« Reply #3 on: February 15, 2024, 10:32:28 AM »
This is the document for the MC0xx-1xx family
https://assets.danfoss.com/documents/206067/BC152986484529en-000701.pdf

For some reason the input and output specifications are in a section with the heading CAN.

Offline Lukey

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Re: AnIn used as 24vdc DigIn
« Reply #4 on: February 15, 2024, 02:18:18 PM »
Thank you acmall.

Yes odd that the heading is CAN

There is mention Middle range and High range, nothing about Low range.

I have only seen the range selection on the multifunction inputs, so I'm not sure about this information.

Overall it does mention max of 36v  ???

I'm not convinced.

Offline sverreo

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Re: AnIn used as 24vdc DigIn
« Reply #5 on: February 20, 2024, 09:20:37 AM »
You can use C1p05 without a problem. The only thing is that if you input 24V it will only read maximum 5V on the input.

Make a simple logic to use this voltage as a digital input. f.ex. greater than 3V "on", and less than 2V "off"

Offline Marbek_Elektronik

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Re: AnIn used as 24vdc DigIn
« Reply #6 on: February 20, 2024, 04:11:03 PM »
I am not sure , but I think c1p05 at a MC024 controller maximum allowes 25V. All other inputs 36V.
Perhaps you ask helpdesk?
Marbek Elektronik, Dipl.-Ing. Bernd Konrad
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Offline Lukey

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Re: AnIn used as 24vdc DigIn
« Reply #7 on: February 20, 2024, 11:31:07 PM »
Thanks all,

Yes I will use a comparison block to simulate a DigIn on pin.

My system is a 24VDC regulated switch mode power supply so I don't expect to see anything greater.
According to the hardware manual AnIn pins rated for 36V

Offline acmall

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Re: AnIn used as 24vdc DigIn
« Reply #8 on: February 21, 2024, 08:52:02 AM »
I am not sure , but I think c1p05 at a MC024 controller maximum allowes 25V. All other inputs 36V.

I think the 25V limit on C1P05 is a difference between the MC0xx-0xx controllers and the MC0xx-1xx versions.

Offline Marbek_Elektronik

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Re: AnIn used as 24vdc DigIn
« Reply #9 on: February 21, 2024, 09:48:37 AM »
Yes, thanks, indeed.
You are right!
Marbek Elektronik, Dipl.-Ing. Bernd Konrad
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