National Instruments NI 6601, User Manual

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Chapter 3 Signal Connections
© National Instruments Corporation 3-11 NI 660x User Manual
Fig u re 3-4 shows the timing req u irements for the Ctr n So u rce signal.
Figure 3-4. Timing Requirements for Ctr n Source Signal
Fig u re 3-4 shows the minim u m p u lse width and period that yo u m u st u se
for the Ctr n So u rce signal. This signal m u st satisfy both minim u m criteria.
If the high phase of the Ctr n So u rce signal is Tsrcpw ns, the low phase m u st
be Tsrcper – Tsrcpw.
Table 3-4. Minimum Pulse Width and Period for Ctr n Source Internal Signals
Parameter
Minimum
Minimum with
RTSI Connector Description NI 6601 NI 6602
Tsrcpw (witho u t
prescaling)
5 ns 5 ns 5 ns Ctr n So u rce minim u m p u lse
width (witho u t prescaling)
Tsrcpw (with
prescaling) 3.5 ns 3.5 ns 3.5 ns Ctr n So u rce minim u m p u lse
width (with prescaling)
Tsrcper (witho u t
prescaling)
50 ns 12.5 ns 50 ns Ctr n So u rce minim u m period
(witho u t prescaling)
Tsrcper (with
prescaling) 16.67 ns 8 ns 16.67 ns Ctr n So u rce minim u m period
(with prescaling)
Ctr n Source
Tsrcpw
Tgatepw
Tsrcper