4-20mA interface...
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Posts: 46,084
Hello Stamp people,
Does anybody have a link to some info on 4-20mA to ADC converter circuits so
that I can read a 4-20mA device with a stamp ?
Thanks,
Chris
Western Australia
Does anybody have a link to some info on 4-20mA to ADC converter circuits so
that I can read a 4-20mA device with a stamp ?
Thanks,
Chris
Western Australia
Comments
will generate a voltage of 5V across the resistor which you can read
with a differential A/D. You shouldn't use a single ended A/D because
you need to read the voltage across the resistor. If all you have is a
single ended A/D, you'll need an op amp across the resistor to measure
the differential.
Al Williams
AWC
* Control 8 servos at once
http://www.al-williams.com/awce/pak8.htm
>
Original Message
> From: Chris Anderson [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=Y9WkThf3QTL5f1jD4rkw-ZlGMLP3hyvi1I7Q_TOHby8nbaukVP7JqADjpT2q4LG13wNaF9zUS5rs2w]fuel@b...[/url
> Sent: Monday, June 16, 2003 6:26 AM
> To: Stamp Group
> Subject: [noparse][[/noparse]basicstamps] 4-20mA interface...
>
>
> Hello Stamp people,
> Does anybody have a link to some info on 4-20mA to ADC
> converter circuits so that I can read a 4-20mA device with a stamp ?
>
> Thanks,
> Chris
> Western Australia
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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> Subject and Body of the message will be ignored.
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Can you provide a part number so I can look up the data sheet.
Original Message
From: Al Williams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=NQnFnccLO8b8p3i9DzcQqTA3kA-UYkjSK07J7RnuCcT2Z3v2E9mIrHEFF-JviZ2x-wnSlCjFCfkCNmY]alw@a...[/url
Sent: Monday, June 16, 2003 8:50 AM
To: basicstamps@yahoogroups.com
Subject: RE: [noparse][[/noparse]basicstamps] 4-20mA interface...
The easiest way is to use a precision 250 ohm resistor in the loop. This
will generate a voltage of 5V across the resistor which you can read
with a differential A/D. You shouldn't use a single ended A/D because
you need to read the voltage across the resistor. If all you have is a
single ended A/D, you'll need an op amp across the resistor to measure
the differential.
Al Williams
AWC
* Control 8 servos at once
http://www.al-williams.com/awce/pak8.htm
>
Original Message
> From: Chris Anderson [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=eZDO7XtjVutGt3BCmR3xePU5FhONY11owYSej__t4hAKT4NrwcrJEn7aaqyieO62ng5HHp-6cguypA]fuel@b...[/url
> Sent: Monday, June 16, 2003 6:26 AM
> To: Stamp Group
> Subject: [noparse][[/noparse]basicstamps] 4-20mA interface...
>
>
> Hello Stamp people,
> Does anybody have a link to some info on 4-20mA to ADC
> converter circuits so that I can read a 4-20mA device with a stamp ?
>
> Thanks,
> Chris
> Western Australia
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the
> Subject and Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
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[noparse][[/noparse]Non-text portions of this message have been removed]
porter.sadler@s... writes:
> Don't understand the term differential A/D.
> Can you provide a part number so I can look up the data sheet.
Differentail referes to two the difference between two inputs where a single
ended A/D reads from one inpu to your ground.
[noparse][[/noparse]Non-text portions of this message have been removed]
http://www.emesystems.com/OWL2face.htm#TLC2543
scroll to approx. the last page.
I usede the TLC... A/D and it works perfect.
Oorspronkelijk bericht
Van: Chris Anderson [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=dQL6su5sypibGMIvdOFuEA7NZWLSG1JCjWJRkShCUCKg9ltWLm6ByqU4efSAc735QzEQ95b2wJT2fnNSRg]fuel@b...[/url
Verzonden: maandag 16 juni 2003 13:26
Aan: Stamp Group
Onderwerp: [noparse][[/noparse]basicstamps] 4-20mA interface...
Hello Stamp people,
Does anybody have a link to some info on 4-20mA to ADC converter circuits so
that I can read a 4-20mA device with a stamp ?
Thanks,
Chris
Western Australia
To UNSUBSCRIBE, just send mail to:
basicstamps-unsubscribe@yahoogroups.com
from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
<http://www.emesystems.com/OWL2face.htm#4-20 ma> might have a bit
of information of use to you. Also
<http://www.emesystems.com/OL2irrom.htm> on tensiometers with the
4-20mA interface.
Usually a differential input is not necessary, because the
termination resistor is placed right at the input of the data logger,
between a (+) input and (common).
Some types of 4-20 sensors are "loop powered", meaning that they
operate using less than 4 milliamps "stolen" from the 4 mA base loop
current. There are two wires from your equipment to the sensor. One
wire supplies a positive voltage usually in the 12-28 volt range, and
the other wire leads back to the top of the termination resistor and
the (+) input, and the bottom of the termination resistor is
connected to common.
Other types of 4-20 mA sensors have their own power supply and two
wires to your ADC, and other types have at least three wires, when
the equipment itself requires more than 4 milliamps for its own
operation. For example, ultrasonic ranging equipment is power hungry.
-- regards,
Tracy
>Hello Stamp people,
>Does anybody have a link to some info on 4-20mA to ADC converter circuits so
>that I can read a 4-20mA device with a stamp ?
>
>Thanks,
>Chris
>Western Australia
as many 4 channel ones.
Meridian 59 is back! Sacred Haven - server 200
www.skotos.net
Original Message
From: "TLD-NV" <peter.christiaen@s...>
To: <basicstamps@yahoogroups.com>
Sent: Tuesday, June 17, 2003 7:00 AM
Subject: RE: [noparse][[/noparse]basicstamps] 4-20mA interface...
> You should check out the following link:
>
> http://www.emesystems.com/OWL2face.htm#TLC2543
>
> scroll to approx. the last page.
>
> I usede the TLC... A/D and it works perfect.
>
>
>
>
>
Oorspronkelijk bericht
> Van: Chris Anderson [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=vPQpBXj59yidQJ53rma0xdOielG4w9IbJ_VXMibnrBGAB3ZZ5Q-VNx_uEGJKXIIw3JLVez2jXTbm]fuel@b...[/url
> Verzonden: maandag 16 juni 2003 13:26
> Aan: Stamp Group
> Onderwerp: [noparse][[/noparse]basicstamps] 4-20mA interface...
>
>
> Hello Stamp people,
> Does anybody have a link to some info on 4-20mA to ADC converter circuits
so
> that I can read a 4-20mA device with a stamp ?
>
> Thanks,
> Chris
> Western Australia
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
> Body of the message will be ignored.
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>
>
>
>
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Body of the message will be ignored.
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>