!)I want to use AD7124_8 for universal analog input. So that I can connect channel number RTD or TC or 4-20mA or 0-10V.Is that possible with Ad7124_8?
2) AD7124 ADC 8 channel differential input is there so that can use channel one for RTD application, Channel two for Thermocouple application,channel three for 4-20mA application, and channel four 0-10v application. So is that possible to configure like this way in AD7124_8?
1 ) The EVAL-AD7124-8-PMDZ board is good.but my problem that how to configure universal analog input schismatic to this board. especially if I want first channel all input like rtd,4-20mA,0-10v, and…
I believe yes it will definitely possible. Especially the RTD and TC inputs as most of the building blocks needed for this type of sensors are already integrated on the chip. We have a reference circuit that will help you start with the design of TC with RTD as its cold junction. Please see below reference circuit.
For the 4-20mA and 0-10V inputs, this will require an external shunt for the current input and attenuator divider for the voltage input.
We also have available AD411x family that will also suit your application.
AD4111/AD4112 are capable of measuring direct 0 to 10V and 4-20mA inputs without the need of any external circuitry. You can use this along with AD7124-4 for your universal input module.
We also have AD4110-1 that allows all inputs above in a single ADC. However, if you require 4 channels I think an external Mux will be needed here.
Please see also all available resources that you may find helpful.
Also, you can take a look at the CN0414 reference design.
Thanks for your replay.
1) CN-0384 circuit note for thermocouple measurement and RTD is used for cold-junction compensation.is that RTD can use for temperature measurement application or otherwise I need to use another RTD?
2) 4-20mA measurement am using external shout resistor only but schismatic have some issues am facing. 0-10 volt am dropping to 0-1v. For this current and voltage measurement am using separate ADC channel so can you refer any schismatic for one channel can measure current and voltage.AD4111seen but for that directly measuring.there no special schematic for voltage and current.
3) I already selected the AD7124_8 for this application.AD4111 cost high will compare to AD7124 price.
4) I need four-channel so how I can use this mux to use this universal analog input.I want to use 16 channel universal analog input then what I need to do?
5) Is there any Arduino compatible code for AD7124_8.
Since you already decide to use AD7124-8 you may want to take a look at this board https://wiki.analog.com/resources/eval/user-guides/circuits-from-the-lab/eval-ad7124-8-pmdz which will be soon released. All the code available for this part can be found a the bottom of this page. We will have soon code available for this board here on Github https://github.com/analogdevicesinc/EVAL-ADICUP3029.
Also, if AD4111 cost id too high for your application you may want to take into consideration AD4112.
1. Actually you can use other CJC other than RTD, but the same RTD circuit and configuration can be use for your RTD sensor even if using this as CJC or for any other temperature measurements. So you can use two RTDs with different functions or other sensor for CJC.
2. Can you clarify what specific issues are you encountering with respect to shunt resistor?
3. I would say both parts performed very well at a reasonable cost and with respect to their target application and system requirements. I wouldn't disagree if you have selected AD7124 as this can be suitable for your application but will require some external components to accommodate all your needs.
4. Can you clarify what it means by 16 channels, does it mean each channel of 16 channels can accommodate any of the RTD, TC, current and voltage measurements? If yes then it would probably required external switches and muxes. Could you check this thread and see if this is something similar to what do you need to do? Do you have any specific target volume for this production?
5. I believe Mihai mentioned that the code will be available soon. But we also have other sample codes that you may find helpful.