Can AM2 read analog from HART device?

Dear Sir/expert,

I choose to use logo basic module 6ED1052-1MD08-0BA1
 and AM2 expansion module 6ED1055-1MA00-0BA2

to make water level control with Level transmitter Which 2 wire 4 to 20mA Hart (E+H) ,Model -FMP51 .

My question is Am2 AI module can connect 4 to 20mA Hart signal, as can I use as 4 to 20mA analog?

Thanks in advance.

Best Regards,

Min

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Split from 4-20mA to HART Conversion.

Hello min;

The short answer is no, you cannot use the AM2 expansion module as a HART module.

The longer answer is that it is strictly an analog module.

https://support.industry.siemens.com/cs/ca/en/pv/6ED1055-1MA00-0BA2/td?dl=en

To operate on HART, there is something missing in the AM2:

"A HART enabled analog input module consists of an ADC and sense resistor to measure the analog current, and a HART modem to modulate an demodulate the HART data". This is from a Texas Instrument document on HART modules:

https://www.ti.com/lit/pdf/sbaa307

A HART transmission is a dual frequency FSK signal that is superimposed over a basic 4-20 mA message.

How HART Works: https://www.fieldcommgroup.org/technologies/hart/hart-technology-explained#:~:text=HART%20is%20a%20bi%2Ddirectional,system%20using%20any%20control%20platform. 

The AM2 acts as a simpel analog input module, it has no HART electronics integrted, so it cannot read HART messages on a 4-20 mA signal. There are no HART-enabled modules in the Logo! offerings.

If you want to workwith HART inut signals, you will heave to go to a different platform, ET 200M (S7-300) or ET 200SP (S7-1200/S7-1500):for example:

• ET 200M (S7-300) analog input module with HART:

https://mall.industry.siemens.com/mall/en/ca/Catalog/Products/10030050?tree=CatalogTree

• ET 200SP (S7-1200/S7-1500) analog input module with HART:

https://support.industry.siemens.com/cs/pd/258569?pdti=pi&dl=en&lc=en-CA

Hope this helps,

Daniel Chartier

Edit: qwazee is quite right. If all you want to do is read the analog input value, and not the HART variables, you can connect with the AM2 module. Very sorry to have misunderstood your question.

D.C.

min min

Dear Sir/expert,

I choose to use logo basic module 6ED1052-1MD08-0BA1
 and AM2 expansion module 6ED1055-1MA00-0BA2

to make water level control with Level transmitter Which 2 wire 4 to 20mA Hart (E+H) ,Model -FMP51 .

My question is Am2 AI module can connect 4 to 20mA Hart signal, as can I use as 4 to 20mA analog?

Thanks in advance.

Best Regards,

Min

HART protocol has a digital communication signal that is superimposed onto an analog signal.

From your question, I understand that you only wish to read the 4 - 20mA signal. You are not concerned with the digital communication component that is superimposed on the analog.

The answer is YES you can use the AM2 to read only the analog component of the signal. Per definition the HART protocol was designed that way that the communication signal does not influence the analog measurement.

Also see the discussion here:
[Difference between 4...20mA and 4...20mA HART signals]

Do keep in mind that it is expected that the field device be configured by using HART. You will need to configure your field device without it. Possibly you have this ability on a built-in screen or you need to have a handheld device. Make very sure that no distributed control blocks (like PID) are activated in the instrument. Speak to your E+H supplier.

 Hello Dchartier,

Thanks for your help and knowledge sharing.

The information you provided are useful  for me.

Yes, actually I would like to read the analog input value, and not the HART variables,

The instrument have option to choose and cost will effect.

Best Regards,

Min

dchartier

Hello min;

The short answer is no, you cannot use the AM2 expansion module as a HART module.

The longer answer is that it is strictly an analog module.

https://support.industry.siemens.com/cs/ca/en/pv/6ED1055-1MA00-0BA2/td?dl=en

To operate on HART, there is something missing in the AM2:

"A HART enabled analog input module consists of an ADC and sense resistor to measure the analog current, and a HART modem to modulate an demodulate the HART data". This is from a Texas Instrument document on HART modules:

https://www.ti.com/lit/pdf/sbaa307

A HART transmission is a dual frequency FSK signal that is superimposed over a basic 4-20 mA message.

How HART Works: https://www.fieldcommgroup.org/technologies/hart/hart-technology-explained#:~:text=HART%20is%20a%20bi%2Ddirectional,system%20using%20any%20control%20platform. 

The AM2 acts as a simpel analog input module, it has no HART electronics integrted, so it cannot read HART messages on a 4-20 mA signal. There are no HART-enabled modules in the Logo! offerings.

If you want to workwith HART inut signals, you will heave to go to a different platform, ET 200M (S7-300) or ET 200SP (S7-1200/S7-1500):for example:

• ET 200M (S7-300) analog input module with HART:

https://mall.industry.siemens.com/mall/en/ca/Catalog/Products/10030050?tree=CatalogTree

• ET 200SP (S7-1200/S7-1500) analog input module with HART:

https://support.industry.siemens.com/cs/pd/258569?pdti=pi&dl=en&lc=en-CA

Hope this helps,

Daniel Chartier

Edit: qwazee is quite right. If all you want to do is read the analog input value, and not the HART variables, you can connect with the AM2 module. Very sorry to have misunderstood your question.

D.C.

In the picture you shared, one of the products are selected. Is this the one you ordered? That selected item has analog and HART separately. For that case you would have no cause for worry -- right?

Do note that internally the analog resolution is between the integer values of 0 and 1000. It depends what your use case is. This measuring range might be too small.

qwazee

 Hello Qwazee,

Thanks for your useful answer and helpful information.

I will choose the built in screen and speak with E+H supplier.

Really thanks for your kind advice.

Best Regards,

Min

min min

Dear Sir/expert,

I choose to use logo basic module 6ED1052-1MD08-0BA1
 and AM2 expansion module 6ED1055-1MA00-0BA2

to make water level control with Level transmitter Which 2 wire 4 to 20mA Hart (E+H) ,Model -FMP51 .

My question is Am2 AI module can connect 4 to 20mA Hart signal, as can I use as 4 to 20mA analog?

Thanks in advance.

Best Regards,

Min

HART protocol has a digital communication signal that is superimposed onto an analog signal.

From your question, I understand that you only wish to read the 4 - 20mA signal. You are not concerned with the digital communication component that is superimposed on the analog.

The answer is YES you can use the AM2 to read only the analog component of the signal. Per definition the HART protocol was designed that way that the communication signal does not influence the analog measurement.

Also see the discussion here:
[Difference between 4...20mA and 4...20mA HART signals]

Do keep in mind that it is expected that the field device be configured by using HART. You will need to configure your field device without it. Possibly you have this ability on a built-in screen or you need to have a handheld device. Make very sure that no distributed control blocks (like PID) are activated in the instrument. Speak to your E+H supplier.

You and I posted at the same time.
Please be sure not to miss my previous answer (and the edited addition).

Good luck with your project.

 Hello Qwazee,

In the picture, if I choose analog and HART separately, will be more cost .

Would like to choose basic 2 wire,4 to 20mA HART(is no additional cost).

Guided radar sensor length about 2000mm in 2 meter cube ground tank for continuous water level monitoring and control pump on /off.

Best Regards,

Min

qwazee

In the picture you shared, one of the products are selected. Is this the one you ordered? That selected item has analog and HART separately. For that case you would have no cause for worry -- right?

Do note that internally the analog resolution is between the integer values of 0 and 1000. It depends what your use case is. This measuring range might be too small.

min min

 Hello Qwazee,

In the picture, if I choose analog and HART separately, will be more cost .

Would like to choose basic 2 wire,4 to 20mA HART(is no additional cost).

Guided radar sensor length about 2000mm in 2 meter cube ground tank for continuous water level monitoring and control pump on /off.

Please explain more about " This measuring range might be too small."

Thanks in advance.

Best Regards,

Min

Your situation seems to be safe.

Assume for this example that a depth of between 1m and 2m can be detected. That means the LOGO! can measure in (2m - 1m)/1000 or 1mm increments. For your case the 1mm measurable  increment would not matter since instability in the water (waves) is even more than that 1mm. You will not switch on the pump for a 1mm level change.

The situation changes when the measurement range is much more than the 1m or if you are critical on making a totalizer for flow in a pipe.