From Friday, April 19th (11:00 PM CDT) through Saturday, April 20th (2:00 PM CDT), 2024, ni.com will undergo system upgrades that may result in temporary service interruption.

We appreciate your patience as we improve our online experience.

Signal Conditioning

cancel
Showing results for 
Search instead for 
Did you mean: 

SCXI 1540 not reading the LVDT Probe values

Hi ,
im trying to configure my SCXI 1540 Module w/1315 terminal block card for excitation voltage 3 Vrms and frequency 2.5Khz using Max
I have LabVIEW Express 7.1 PDS - SCXI-1000 Chassiss - along with PCI-6254 is attached to the 1540 card.
MAX says it recognizes all the cards in the chassiss. The LVDT Probe when connected to the SCXI 1540 does not show any change in values even when the probe is moved .
The probe has been checked individually as well as the the excitation signal on the SCXI 1540 module channel has been checked on the CRO.(Though in MAX we have set the excitation frequency to 2.5KHz it shows  a frequency of 7.8 KHz).
 
The PCI 6254 has two connector inputs Connector0 is from the SCXI  and Connector1 is from  SCB 68 module (Digital signals from the client main panel are routed to the SCB68 terminal block).
 
Plz Help
 
Tanisha
0 Kudos
Message 1 of 2
(3,041 Views)

Hello Tanisha,

There are a few things we should check.  First, we need to make sure that the chassis is setup correctly in MAX.  Highlight the entry for the SCXI Chassis, right-click and choose properties.  Make sure that on the chassis tab of the configuration window, the correct Communicating SCXI Module Slot is chosen.  Whatever slot you have connected the cable from your PCI-6254 to should be listed here.  Also make sure that the Chassis Communicator is correctly listed as your PCI-6254. 

The second thing to check is to make sure that the external connections are correct.  The best way to do this is to check the connection diagram in MAX.  To do this, create an LVDT task (right-click on Data Neighborhood to do this) and then specify all your settings correctly, and then at the bottom of the screen you will see a connection diagram tab.  If you do not see this tab, you have a version of NI-DAQmx that was released prior to this feature and you can update to the newest version here.  I am attaching a picture of what it looks like on my computer. 

How are you measuring an excitation frequency of 7.8 KHz?

Please check these things and get back with us.

Thanks,

Laura

0 Kudos
Message 2 of 2
(3,031 Views)