Synchronizing USB-8473S CAN Device with a DAQ Device in LabVIEW Hardware: SCXI>>Modules>>SCXI-1600
Problem: I'm trying to synchronize my USB-CAN device with a SCXI 1600 and in the process I'm getting an error -1074388697 at ncAction.vi. What am I doing wrong and how can I fix this error?Solution: USB-8473s synchronizes via RTSI or any 1/10/20 MHz timebase source. 847x sync series have a RTSI7/RTSI Clock, which selects the RTSI line 7 as source (input) of the connection. For PCI and PXI form factors, this receives a 20 MHz (default) timebase from another CAN or DAQ card. For example, you can synchronize a CAN and DAQ E-Series MIO card by connecting the 20 MHz oscillator (board clock) of the DAQ card to RTSI7/RTSI Clock, and then connecting RTSI7/RTSI Clock to Master Timebase on the CAN card. For PCMCIA form factor, a 10 MHz timebase is required on RTSI7/RTSI Clock. For synchronization with a PCMCIA DAQ card, this is done by programming FREQOUT signal of the DAQ card to 10 MHz, then wiring FREQOUT to the RTSI7/RTSI Clock of the CAN card. Sometime a USB-CAN or a USB-LIN device fails to read synchronization clocks at 20 MHz and throws an
847x sync series also has a RTSI0 which is the trigger source terminal. Please refer to USB-CAN and USB-LIN Specifications for details on synchronization triggers. An SCXI 1600 module has the 20 MHz or 100 kHz internal timebase that generates SI SOURCE signal, however these clocks are used to time the generation of the AI SAMP CLK signal. These two timebases cannot, therefore be used to synchronize an external device. You will have to use a DAQ device to synchronize CAN data transfer. For synchronizing, you will first route the internal timebase and trigger of a DAQ device to a PFI line using DAQmx Connect Terminals.vi. Then these two signals will be connected to RTSI lines on CAN device by using the ncConnect Terminals.vi. Please refer to following figure and Sync CAN with DAQ example program for further details.
Related Links: AE KB 38B9S22G: Can the SCXI-1600 be used in a Multi-Chassis Configuration? Attachments:  Sync CAN with DAQ.vi
Report Date: 08/31/2007 Last Updated: 12/10/2007 Document ID: 4CUE3U1S |
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