connecting two scxi 1121 modules in one scxi 1000 chassis

[peco23]

Hello,
Im new here, and I need some help...

my configuration is:

Scxi 1000 chassis
two scxi 1121 cards
two scxi 1321 modules,

I need to acquire 6 channels, four in one module and two in the second module, I have connected this cards to the chassis and used the MAX to configure it,
i have added the chassis in the devices and interafces MAX and configured the modules, I dont know where is the problem, but I cat acquire the signal only
from one scxi card which is connect directly to daq board, can you help me, step by step, how can i connect configure these cards to measure the strain from both modules.

regards Peco23

[jaced]

Hi Peco23,

How are you “testing” your system, are you using the test panels in MAX or are you creating a Task and adding the channels of interest? If you are using test panels to you see good data when testing one card and then nothing when testing a channel on the other? Or do you receive an error? If you are using a task you should be able to simply add additional channels to the task as long as you are only using one DAQ card. Another possibility is that you did not configure the communications slot when you first configured your chassis. This can be peformed by right clicking on your chassis in MAX under Devices and Interfaces and selecting properties. Within the properties window select the Chassis tab and configure the SCXI module slot that you have the DAQ card connected to as the communicating slot. I hope this helps please post back with the exact behavior along with some screenshots of your max configuration

[peco23]

Im testing my system in MAX using test panels, I have added the chassis and the modules in the "Devices and interfaces"
and configured it. I post you some screenshots from the MAX. When I tested the first module (SCXI-1321)
in the second slot which is connected to the daq board, every channel give me a good signal ("scxi1121_2slot.jpg"),
 but the other card give me wrong signal on the second channel ("scxi1121_2slot_2channel.jpg"),
only the first  channel give me good signal ("scxi1121_3slot.jpg"). In my application Im using 12 strain gages,
it is critical application, where is high temperature of the oil and high pressure and I thing one "cu wire"
is broken, I will check it. I have another question: what is "multichassis daisy chain index"? Should
I set this only if I have more than one chassis ("slot2_cabling.jpg")? And how and where can I set the
max and min input limit ("scxi1121_2slot.jpg"), I can set it only for +-50m, when I try to set it to +-5 I get error
(-200077). By the digital I/O I get error -200159 ("pci_mio_digital_io.jpg"), should I set some lines or ports
to communicate with the second module? And when Im testing the daq board using test panel I get different
signals, it is OK ("pci_mio_ch1.jpg", "pci_mio_ch5.jpg")?

Thank you in advance

Peco23

[jaced]

Hi Peco23,

It sounds the broken wire may be the culprit in the malfunctioning channel. If you do not locate a bad connection, then I suggest trying to move a known good signal to channel two, by doing this it is my hope to isolate the cause of the issue, be it a bad channel or a bad signal. The Multichassis daisy chain index refers to the capability of SCXI to have more than one chassis connected in a “daisy chain”. Based on your configuration you need not worry about this setting. The Max/min input limits are determined by the gain settings. Have you verified that the jumper settings on your SCXI-1121 match those that you set in MAX?  Please refer to page 2-8 of the SCXI-1121 User Manual here for more detailed information on the proper input channel jumper settings. The error you receive on your DAQ card is explained by this knowledgebase entry. The test panels of the DAQ card should not be used for this application, you should use the test panels for the SCXI. I hope this helps!!

[peco23]

Hi JaceD,

Thank you for the answer, it helped me a lot, the first problem was that two of the wires were broken, I have fix it. The second was the gain on the SCXI 1121 was set to 2000, and I can´t correct acquire the signal. Now everything works well.


Regard Peco23