constatnt 7V on AO channels of PCI cards

[kafivet]

I am using NIdaq mx and labview 8,

the problem is that the Analog out channel gives 7 V  as off set , When the voltage is increased from MAX  , say 1 v than it adds 1+7 to give 8 v and so on.

please tell me what may be the problem?

waiting

thanks

haider

[TheWoost]

Hi haider,

That is strange behavior that you are seeing.  What is the PCI DAQ device that you are using, and what version of the NI-DAQmx drivers do you have installed?  How are you reading the output signal from your device?  Is this behavior occurring on all analog output channels of the device?  If you do a self-calibration of the device in MAX, does the behavior change?

Regards,
Andrew W
National Instruments

[kafivet]

Sir

devices are PCI-6704 ,PCI-6110

I am reading using a multimeter , and tried a scope also  but the response was same

yesterday the case was little bit different that , when I used both the cards on another PC (pc1) , they are working properly ,i.e. they are not outputing the 7V on start up,or as off set and

again I installed in the previous IBM server computer (pc2) (windows server installed), they are behaving the same 7V out constantly.

I tried also doing self calibration and Traditional daq , but bare no fruit.

the two systems are described as follows:

PC1 (where the cards are working properly                            PC2 IBM server(wher the problems occures)

DAQmx ver.   7.0.0f0                                                                            DAQmx ver.   8.3.0f0 

Trad Daq ver 7.0.0f8                                                                             Trad Daq ver 7.4...

MAX ver         3.0.0.3014                                                                       MAX ver         4.1.0.3001

[kafivet]

Sir

devices are PCI-6704 ,PCI-6110

I am reading using a multimeter , and tried a scope also  but the response was same

yesterday the case was little bit different that , when I used both the cards on another PC (pc1) , they are working properly ,i.e. they are not outputing the 7V on start up,or as off set and

again I installed in the previous IBM server computer (pc2) (windows server installed), they are behaving the same 7V out constantly.

I tried also doing self calibration and Traditional daq , but bare no fruit.

the two systems are described as follows:

PC1 (where the cards are working properly                 PC2 IBM server(wher the problems occures)

DAQmx ver.   7.0.0f0                                                                            DAQmx ver.   8.3.0f0 

Trad Daq ver 7.0.0f8                                                                             Trad Daq ver 7.4...

MAX ver         3.0.0.3014                                                                       MAX ver         4.1.0.3001

[Kenn_N]

Hey haiderabbas,

This is very strange indeed.  To be sure I am understanding this issue properly.  You insert both cards into PC1, and BOTH cards work properly.  Then you insert them into PC2, and BOTH cards present the same behavior.  Is that right?

First off DAQmx is not officially supported in Windows Server.  You didn't explicity say what version of the OS that is on the IBM, but it sounds like it might be Windows Server 2003 or something earlier.  These OS's are not supported.  That said, this behavior is rather odd.  The odd thing is that the design of those  two cards is so fundamentally different, that I am surprised that the same behavior follows both.

Second, the only thing that I can think of to explain this phenomena is ground loops.  Is the scope and the IBM PC plugged into the same wall socket?  What about the DMM is it plugged in, or a portable battery powered DMM?  Not sure what else to say or ask, but you could also install the latest version of DAQmx, which is 8.5 and see what happens with that installed.

Regards,

[kafivet]

of course sir

the OS on IBM is Windows server 2003,

When I insert either both or Single or one by one the behaviour is same.

i.e.  on IBM comuter they dont work for AO

and another PC they are working properly.

The DMM IS portable battery operated. so no chance of ground loops as i think.

the only option I will try is DAQmx 8.5  and by removing OS Windows server 2003

further If You get some solution

I will wait

Haiderabb (haideruet@hotmail.com)