TC-2095 thermocouple disconnect detection

[drakkar]

Hello,

TC-2095 has a feature that drives a thermocouple reading high if a thermocouple is disconnected.

However some of the channel on the TC-2095 stay high (full scale) and some, actually most of them go full scale and than go to -6 in a matter of few seconds.

All channel are configure the same in the back of TC-2095.

Is there an additional setting in MAX or in the console that needs to be configured?

Thanks

Matthew

[Patrick_NI]

Hi drakkar, 

For information on how to configure the open thermocouple detection, please see the following documents:

Information about how to set up the open thermocouple detection (per module)

http://digital.ni.com/public.nsf/allkb/C2C7AB329ABC608986256D3D004C86AE

Hardware settings can be found on page 5 of the TC-2095 manual

http://digital.ni.com/public.nsf/allkb/86256A47004E16D186256B45006F561C

Please look over those documents and confirm you are using the feature correctly.  To my knowledge, you should not have to set up any additional settings in MAX, as long as you are correctly identifying your SCXI module and terminal block correctly.

[KD2]

Using a TC-2095 with grounded thermocouples, I have the switch settings as: pull-up on, ground reference off and everything seems to function correctly when the thermocouples are installed. However, when I perform disconnect checks from the TC-2095 module with these thermocouples, some of them rail high, while others rail low, when I would expect all of them to rail low because the ground reference is off. Patrick, can you explain why this may happen?

[Wild_man]

KD2,

This is a fairly old thread, Patrick seems to have been inactive on the forums for a while, but perhaps I can help.

Leaving the ground reference turned off will allow you to detect an open connection to a ground referenced thermocouple, but will leave the negative line floating (unpredictable.) In most cases you should have both the pull-up and the ground reference turned on so that you are guaranteed a 5V differential signal if disconnected.

Pages 5 and 6 of the manual show the possible configurations

http://www.ni.com/pdf/manuals/321731b.pdf

[sam3456]

How i can use TC-2095 Module with PXI Chassis or directly to PC with labview software