How do I use a thermocouple with a SCB 68

[Haavikon]

My system consists of a PCI-6024E card SCB 68 and Labview 7. I want to connect a T type thermocouple to the SCB box and measure (hopefully) an ambient temperature. I have tried connecting to channel 0 in differential and single ended mode and have changed the settings on the switches in the SCB 68 when I use the DAQ assistant to set up my measurement it reads something like -1100oC. What am I doning wrong here
Hope someone can help
Dan

[SimonS]

Hi Dan

Try doing a few tests on your system to try to work out what is happening.

First test the DAQ card is working correctly, by using it to test a known voltage. Apply a voltage from a power supply to the analogue input channel, then use the test panel in (MAX) Measurement and Automation Explorer to read it.

Next connect up your thermocouple and set-up the SCB-68 switches to use the on-board CJC sensor. Try Creating a DAQmx Global channel in MAX to measure the thermocouple. Make sure you specific thermocouple measurement, the correct input channel and T-type thermocouple. Use the channel test-panel to check the temperature is correct.

Please post what you find from trying this.

[Haavikon]

Channel works fine
I tried to set up a channel in MAX Measuremment and Automation explorer. Set the type to T and the CJC source to built in and tried to test the measurement got the following error

Error -200077 occurred at DAQ Assistant

Possible reason(s):

Requested value is not a supported value for this property.

Property: AI.Thrmcpl.CJCSrc
You Have Requested: Built-In
You Can Select: Constant Value, Channel


--------------------
Error -200477 occurred at DAQ Assistant

Possible reason(s):

Specified operation cannot be performed when there are no devices in the task.
Dan

[locator299]

I am fairly new at this, but I believe the Cold Junction setting in the SCB-68 uses Channel 0 in MAX Measurement and Automation Explorer. So, your thermocouple would have to go on Channel 1.

[R_J]

Hi

I am checking the continuity between different pins of the connector (C). The multimeter   is showing short circuit if the one end of the 68-pin cable is connected to the connector box & the other end is connected to the PC.

& The multimeter shows open circuit if I disconnect the one end of the 68 pin cable which is connected to the connector box.

Please find the attached word documents for more clearification.

[R_J]

Hi

I am checking the continuity between different pins of the connector (C- (Check the attached word documents)). The multimeter   is showing short circuit if the one end of the 68-pin cable is connected to the connector box & the other end is connected to the PC.

& The multimeter shows open circuit if I disconnect the one end of the 68 pin cable which is connected to the connector box.

Why it is happening ?

Please find the attached word documents for more clearification.

Please reply as soon as possible

regards

raman

[AnalogKid2DigitalMan]

What are the specific pin numbers and what DAQ card are you using?

On many DAQ cards there are ground lines that are all tied together on the DAQ card, these would definitely show a short circuit when the cable is connected to the DAQ card.

[R_J]

hi

Thanxs for reply

I am using PCI-6711 & PCI-6723 Daq Cards.

I wants to know the basic reason behind this.

If there is any website link or documents then please send it to me

thanxs

Bye

[McKala[DE]]

What pins are you checking?

Regards,