Chapter 8
Real-Time System Integration Bus (RTSI)
Analog Output Series User Manual
8-4
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source. If you configure the device to use the internal timebase, you also
can program the device to drive its internal timebase over the RTSI bus to
another device that is programmed to receive this timebase signal. The
default configuration is to use the internal 20MHzTimebase signal without
driving the timebase onto the RTSI bus.
(NI DAQCard-6715 only)
The NI DAQCard-6715 does not interface to the
RTSI bus. It can only directly use its own internal 20 MHz timebase as the
primary frequency source.
Synchronizing Multiple Devices
With the RTSI bus and the routing capabilities of the DAQ-STC, there
are several ways to synchronize multiple devices depending on your
application. NI recommends that you use a common timebase as the
MasterTimebase signal and share any common triggers in the application.
One device is designated as the master device and all other devices are
designated as slave devices.
The 20MHzTimebase on the master device is the MasterTimebase signal
for all devices. The slave devices pull this signal from the master device
across the RTSI trigger 7 line. Slave devices also pull any shared triggers
across an available RTSI trigger line from the master device. When you
start all of the slave devices before starting the master device, you have
successfully synchronized your application across multiple devices.