SCXI 1000 always reading lower limit

[QuantumAnd]

Hi Everybody,

I'm working on an old system to make some I-V measurements.

The hardware is: NI 6052E DAQ board, connected (without any accessories) to a SCXI 1000.

On the SCXI chassis I have 3 1120 modules, one with a 1338 terminal block and two with 1320 terminal block.

The system has worked fine for several months, then suddenly we had this issue:

all the channels of all the modules are reading the lower limit voltage (-0.5 V in my configuration, because gain set to 10).

I have tried to configure again the hardware by MAX, but nothing has changed.

I have checked the fuses on the back but they seems alive.

Any idea on which could be the problem??

Thanks

[alamanna]

Hi,

since the system has suddenly stopped working properly and if I am not mistaken for no apparent reason, the most plausible hypothesis is a failure of the DAQ board or the SCXI chassis.

Since the issue affects all the channels of all the modules, I doubt it would make sense to do cross-tests with the three 1120 modules, even if they use two different types of terminal blocks.

Regards,

Alessia

[QuantumAnd]

Hi Alamanna, thanks for your reply.

Today I have tried the modules (1120 with 1320 and 1338 terminal blocks) on a different chassis (1001), bu t the result is the same: always lower limit detected. So I guess the problem is on the DAQ board.

I have three questions, if you can help me:

1) I use the 6052E board also to output a voltage signal (0-10 V d.c.), and this is working fine. Is it possible that the board works for the output but not for the input?

2) I see the 6052E is obsolete. Can you suggest me a new board with the same features?

3) In the MAX tab for the SCXI chassis configuration, there is a value called "Daisy Chain number". What is it?

Thanks in advance

[alamanna]

Hi,
I'll try to answer your questions:
1) Yes, it's possible.
2) Based on the following NI 6052E Family Specifications

Maximum Number of Single-Ended Analog Input Channels: 16
Maximum Number of Differential Analog Input Channels: 8
Maximum Sample Rate: 333 kS/s
Analog Input Resolution: 16 bits
Number of Analog Output Channels: 2
Maximum Update Rate: 333 kS/s
Number of Bidirectional Digital Channels: 8
Number of Counters/Timers: 2
Analog Input FIFO Buffer Size: 512 samples

a PXI Multifunction I/O Module model currently on the market that should ensure performances not inferior to 6052E is PXI-6281, which presents the following specifications.

Maximum Number of Single-Ended Analog Input Channels: 16
Maximum Number of Differential Analog Input Channels: 8
Maximum Sample Rate: 625 kS/s
Analog Input Resolution: 18 bits
Number of Analog Output Channels: 2
Maximum Update Rate: 2.86 MS/s
Number of Bidirectional Digital Channels: 24
Number of Counters/Timers: 2
Analog Input FIFO Buffer Size: 2047 samples

You can examine the alternatives and select the specifications you care most in the drop-down menus to evaluate if that's really the model that is right for you. But I recommend you to contact your local sales representative through ni.com/contact; he will support you in the best way in making the right choice.

3) Searching internal NI resources I found a document explaining that the daisy chain index (not "number") is

the chassis's location with respect to the DAQ card. If it is the closest chassis to the card, its index would be 0. If its the second closest, it's index will be 1.

I am attaching a screenshot with some more information.

I hope all this helps you!

Regards,

Alessia

[QuantumAnd]

Thanks a lot Alamanna!