Can I use two SCXI-1520 modules with one M Series DAQ card?

[kmcdevitt]

I am running LabView RealTime 7.1.1 on a PXI Combo chassis as shown here:

 pxi slot 5:  PXI-6733  (used to test the slot 3 SCXI-1520 inputs)

pxi slot 6:  PXI-6733  (used to test the slot 3 SCXI-1520 inputs)

pxi slot 7:  PXI-6254   (two connectors, each going to the back of a SCXI-1520 in parallel mode)

pxi slot 8:  PXI-6031E  (controls the SCXI-1100,1102 through the PXI:SCXI backplane)

scxi slot 1:  SCXI-1100  (operates in multiplexed mode with the slot 8 PXI-6031E)

scxi slot 2:  SCXI-1102  (operates in multiplexed mode with the slot 8 PXI-6031E)

scxi slot 3:  SCXI-1520  (operates in parallel mode with the slot 7 PXI-6254 left connector)

scxi slot 4:  SCXI-1520  (operates in parallel mode with the slot 7 PXI-6254 right connector)

Is it possible to use two SCXI-1520 modules, both running in parallel mode, connected to a single PXI-6254 M Seriaes DAQ card?

[Ryan_V[DE]]

kmcdevitt,

Absolutely! The trickiest part about this setup is that you must specify the channels on your 6254 which you wish to use for communication with the 1520s. One 1520 will use channels 0-7, the other will use channels 16-23. This KnowledgeBase provides more information on this setup. Please let me know if I was not clear, or if you have any more questions.

Hope this helps,

[Ryan_V[DE]]

kmcdevitt,

I forgot to mention that this is not an officially supported configuration. In order to get this to work, you will not be able to use Simultaneous Sample and Hold on your 1520s. You will have to disable it programmatically (test panels will not work). This can be done by selecting the active channels, then disabling the analog input sample and hold circuitry (DAQmx Channel Property Node->Analog Input->General Properties->Advanced->Sample and Hold Enable (see picture). Also note that you must have a version of the DAQmx driver greater than 7.3. Please let me know if you have any difficulties with this.

Message Edited by Voltage Viper [DE] on 12-21-2005 04:06 PM