Our full technical support staff does not monitor this forum. If you need assistance from a member of our staff, please submit your question from the Ask a Question page.


Log in or register to post/reply in the forum.

Nan in Pt100 Sensors with CR1000 and AM16/32


RamonLopez Aug 3, 2009 11:50 AM

Hi,

I have a big problem.
I use one CR1000 and AM16/32 to measure 8 pt100 sensors in 4 wire mode. (using 4WPB100).

The data in tables is saved every 10 minuts.

Some values (3 o 4 for day) in data tables are NaN, INF, or big number 4e10. the rest of values are correct.

What is the problem?.

The code is here...

PortSet (3,1)
PulsePort (4 ,35000)
BrHalf4W(RS_R0,1,mV25,mV25,1,Vx1,1,2035,True ,True ,0,_50Hz,1.0,0)
PRT (Tsoil1,1,RS_R0,1.0,0)
...
same code 8 items (Tsoil1, Tsoil2,Tsoil3....)
PortSet (3,0)

The Scan time is 10 seconds.


aps Aug 3, 2009 02:06 PM

Do you have a record of the battery voltage of the system. I ask as up until approx 6 months ago the AM16/32 used relays that would not switch if the voltage was much lower than 12V, a voltage which is higher than the minimum for the logger.

A design change made recently uses newer relays that work down to 9 V or so.

If battery voltage were the issue though you would expect several measurements to be bad together.

Another possibility might be operating system related, especially if the above measurements are in a slow sequence.

As always we'd recommend you try the latest firmware from

www.campbellsci.com/downloads


wpns Aug 3, 2009 04:21 PM

Is it possible you've got a poor connection somewhere? Is it always one sensor, or all of them? If it's all of them then it's in the Mux or the wiring between the mux and the logger.


RamonLopez Aug 4, 2009 08:18 AM

Hi,
thanks aps and wpns, but, the problem remains,
version of the operating system is 13

and show some values of voltage and internal temperature of the datalogger

15/07/09 13:30 UTC 12.93Volts 39.19ºC (NAN values)
15/07/09 20:30 UTC 12.44Volts 35.14ºC (NAN values)

16/07/09 21:30 UTC 12.35Volts 31.57ºC (NAN values)

17/07/09 Ok all day.

18/07/09 8:30 UTC 12.20Volts 27.42ºC (NAN values)
19/07/09 20:30 UTC 12.41Volts 36.04ºC (NAN values)

the rest of values are correct ( every 10 minuts)

the wiring connection is ok, everything worked ok, until upgrade the software acquisition (the file .CR1).
PT100 sensors only fail the rest works fine in the mux.


The comments in the file. CR1 can cause a malfunction?
The program. CR1 has a size of 54kbytes, is it very big?

I use one NL115 and one CF card.

Thanks


aps Aug 4, 2009 01:30 PM

You did not say if this code is in the main program or a slow sequence? If in a slow sequence I would recommend the OS upgrade.

Other than that can you confirm what the maximum temperature is you are expecting to measure.

Comments in the CR1 program and the size of the file should not be issues.


jra Aug 4, 2009 02:03 PM

Mr. Lopez,

You said "everything worked ok, until upgrade the software acquisition (the file .CR1)."

What changed in the program? Compare the old working program with the new one.

Regards,
Janet

Log in or register to post/reply in the forum.