PXI reset on computer power loss

[nleaf]

Hello,

My setup is a NI PXI-1033 chassis with 3 6230 M series cards.  The application that they are intended for is sensitive to fast voltage changes, so that any voltage source that is connected to it must be stable over the period of quite a few days.  My issue is that any time the computer loses power, all of the cards reset to a default output.  I feel like this might be a simple setting, but I haven't had any luck searching the manual or these forums.

Further information:
NI DAQ 8.5
Labview 8.2

Thanks in advance for the help.

[Rimasaurus]

Hi,

Welcome to the NI Forums!  One suggestion I have is to change the power settings of your computer so that the hard drive doesn't automatically shut down and the system doesn't go to standby after a certain period of inactivity.  The digital output lines have digital programmable power-up states, which will allow you to configure the output settings at power-up.  More information about the programmable power-up states can be found on page 6-2 of the NI 6230 User Manual. 

Regards,

Rima

[nleaf]

Changing the power settings would prevent the output voltages from reverting to 0 when the computer went into standby, but it would not help in the event of a crash.

I was not able to find any mention of analog power up states in the 6230 manual.  Even if it is possible to set the power up state, my VI would have to set it every time it changed a voltage to be sure that that the voltage outputs remained constant if the computer crashed.  Intuitively, this seems like it would add a lot of overhead to my VI.

Here's a little more background on our current and desired hardware set up:
At the moment, we have a number of independent voltage sources and meters (e.g. Yokogawa 7651s and Keithley 2002s) controlled over GPIB.  Since they are independent of the controlling computer, if the computer crashes they don't change their voltage.  We'd like to replace this with three NI PXI 6230 M series cards in a PXI-1033 chasis.  What I need for this system to work is for the analog output voltages to remain constant if the computer crashes in order to prevent damage to the device we are working with.  In my current setup, if the computer crashes or shuts down for any reason, all of the analog outputs go to 0.

Please let me know if I left out any helpful details.

[Rimasaurus]

Hi,

When your computer shuts down or reboots, the analog output of the DAQ cards will automatically return to its default state of 0V.  The outputs go to 0V so that the cards can be swapped out safely.  You may use a power supply to keep the analog outputs constant.

Rima