Hi,

i connected as per attach picture and my program is [BEGIN S1=0,15"m" RA2S 1#L(S1) END]. the return value is 'UnderRange'
sensor output is 4~20mA. we have connected with multi meter(amp reading) and given success result.

Please advise

Regards,
Rosli

Good morning wanrosli,

You need to allow the sensor to warm up.
The internal resistor is switched in and out of circuit as the channel is read so you need to use the measurement delay to allow the sensor to warm up.

If you are reading a sensor that is part of a control circuit or need to be read relatively quickly then use an external shunt resistor.

Cheers

Roger

Hi wanrosli,

There is a relay that separate internal shunt resistor to your sensor.
The relay will only close when measurement is due and standard measurement delay for this relay is 10 ms.
The delay might be too short to enable your sensor to give reading.

As Roger said you will need to increase measurement delay.
Please try to use 1 second delay with this command [BEGIN S1=0,15"m" RA2S 1#L(S1,MD1000) END].

If you don't get the reading yet, please increase MD step by step (note: there is a sensor that need up to 13000 ms to get a reading).
It is not a good practice as you may hinder other schedule.
So it is recommended to use external shunt resistor (configuration C1 (shared) or C2(independent)).

Best regards,
Rudy Gunawan

Hi Rudy and Roger,

For your info, this sensor taking about 1 minute to have the reading in between 4-20mA.
therefore, the command i should use is
BEGIN S1=0,15"m" RA2S 1#L(S1,MD600000) END

Is it correct ?

Thanks for your reply
WanRosli

Hi Roger and Rudy
MD1000 - 1 sec, that means MD60000 - 60 sec :)
i need to read it in 5 minutes interval, so i will choose to use internal shunt.

I'm outside from my lab, once i tried it, i will informed the results.
Thanks!

Regards,
WanRosli

Hi wanrosli,

Yes, you are correct.

Best regards,
Rudy Gunawan

Dear Rudy,
i have tried to increase the MD reading but i didn't get the result.

So. i tried to use external shunt,470 Ohms, connecting to Channel 1 * and # termination and series with ammeter to check the current through it.

The result of reading is :
a) Before 30 sec : 3.4 mA (ammeter reading is 0.003 A)
b) After 30 sec : OverRange ( ammeter reading is 0.018A )

Wiring connection referred :C2 – Independent Current Inputs with External Shunts

Could we get the reading for OverRange at Data Taker ?

Regards,
W.Rosli

Hi,

i already get the reading of amp by put Channel option: A(attenuation) inside the program.

The result is same with my multi meter reading.

Thanks ,
Wan Rosli

Good morning WanRosli,

When you put in the external shunt resistor did you rewire the sensor so the sensor was powered all the time?
Also when using an external shunt the DT80 default shunt is 100 Ohms, did you enter your shunt value into dEX?

Lets try and get this sensor working by having it powered all the time.
Can you please wire it up as per figure C3 on page 304 of the manual (UM-0085-B8) with a 100 Ohm resistor across the / # terminals.
Send a simple dEX configuration to the logger reading the sensor as current once per second (Make sure you have the external shunt between the /# selected)
The sensor should then read as 4 mA at no input and 20 mA at full input.

Start the configuration running on the logger and then turn on the power to the sensor and time how long it takes for the reading to become stable.
This will be the warm up time for this sensors. It will also tell us if the reading is stable and the sensor is working correctly.

Once we know this we can then look at configuring the sensor for low power using the internal shunt.

Cheers

Roger

Dear Roger,

i have successfully get the reading of Amps by doing this program
1*L(470,A)
Therefore, i will use external shunt (470 ohms) for my wiring

Thanks
WanRosli