scc 2345 and lp04

[E@bio]

I have connected the signal from and accelerometer amplifier to an SCC-LP04 filter module.  The module is located in slot J1 of an SCC-2345 enclosure with the external power supply and DAQ cable connections on the rear of the enclosure.  The DAQ card being used is a PCI 6221.

I am getting a flat line response sitting at 10.5 volts when I look at the signal in MAX.  If I unplug the signal from the accelerometer the output seen in MAX remains at 10.5 volts.

In the current setup all the components are brand new.  I have used similar combination of hardware in the past with out any problems.  I am at a loss as to what is wrong. 

[BrowningG]

Hello E,

Thanks for contacting National Instruments. 

It is normal for an open connection being measured by a DAQ card to return a railed voltage value.  This is due to the fact that the inputs at this point are floating.  Most likely there is an issue with the hardware setup. 

Try running the DAQ Diagnostic Utility for your DAQ card; this will attempt to locate any errors in the DAQ device.  Also try connecting a known voltage source directly to the DAQ card and to the LP04.  If the voltage rails when using the LP04, but not the DAQ card, it is most likely an issue related to the LP04. 

We have seen case where the LP04 when used in a SC-2345 with a PWR02 connector has caused a malfunction.  To attempt to get around this, try connecting the PWR02 module to the SCC-2345 before you plug it into the wall.  This will allow for the +/- 15 Volt power supply rails to come on at the same time. 

Please post back if you have any questions.  If this troubleshooting does not work for you, contact our technical support to speak to an Applications Engineer who can determine if the device needs to be returned for repair.