01-15-2008 06:05 AM
Hi,
I have a compact field point system to record t° measurements on a machine (to replace a YOKOGAWA paper recorder system)
This machine is equiped with Thermocouple and RTD sensor
TC acquisition boards are CFP-TC-120. Readings are ok
RTD acquisition boards are CFP-RTD-124. Reading are nok : see picture attached
With the previous YOKO system readings were stable and did not show any fast variations.
If i take resistance measurements, value is also stable.
CFP-RTD-124 used is revision H (187208H-02)
In advance thanks for your support.
Regards
Stéphane
01-15-2008 08:19 AM
To me, it looks like just a little bit of electrical noise. You've collected 10's to 100's of data points in a 2 second period and it looks like the results are +/- 1 degree. (The VI isn't clear as to whether this is °C or °F)
I might be wrong, but I think the thermocouple modules have some internal filtering to eliminate noise. I've never used the RTD module to know, but perhaps it doesn't. Or maybe there is a setting in MAX to turn it on.
Does your temperature change so rapidly that you'd need to read numerous data points per second? The screenshot doesn't look like it is. One possibility would be to so some averaging across multiple data points and plot that result.
04-16-2008 09:33 AM
04-16-2008 09:33 AM
04-16-2008 09:33 AM
04-16-2008 09:33 AM
04-16-2008 09:36 AM
01-19-2012 11:16 AM
Hey there, I'm also having the same problem as you do. What i did to solve it was to change the cpf-RTD-122 power supply for a DC variable lab Power supply, that corrected the issue right away. now what im trying to do is to find out why it won't work with the field point power supply or with another power supply.
Regards
Elmer Rodriguez
R&D Engineer