Rtsi Triggers - National Instruments NI 660 Series User Manual

trigger signals between several functions on as many as five DAQ devices
in the computer. In a PXI system, the RTSI bus consists of the RTSI bus
interface and the PXI trigger signals on the PXI backplane. This bus can
route timing and trigger signals between several functions on as many as
seven DAQ devices in the system. For a RTSI connector pinout, go to
ni.com/info

RTSI Triggers

TIO devices require a frequency timebase for its operation. This frequency
timebase must come from the onboard crystal oscillator and is required
even if the device is receiving a MasterTimebase signal from the RTSI
trigger bus. Any TIO device can drive its 20MHzTimebase signal onto the
RTSI Trigger 7 pin. Although some TIO devices have a 80MHzTimebase
(such as the NI 6602), the RTSI bus cannot carry the 80MHzTimebase
signal for bandwidth reasons. By default, TIO devices do not drive the
RTSI Trigger 7 bus clock line.
Figure 3-8 shows the RTSI signal connection scheme for PCI TIO devices.
PXI TIO devices use PXI trigger line 7 as their RTSI clock line. The
maximum timebase provided by the PXI TIO device is phase locked to the
10 MHz PXI backplane clock. By using other PXI modules that phase lock
their board clocks to the 10 MHz PXI backplane clock, you can better
synchronize operation in a multi-module PXI system. The phase locking is
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and enter .
rtsipin
Trigger <0..6>
RTSI Trigger 7
Figure 3-8. RTSI Signal Connection Scheme for PCI
3-15
Chapter 3 Signal Connections
CtrnSource
CtrnGate
CtrnAux
CtrnInternalOutput
20 MHz Timebase
Master Timebase
NI 660x User Manual