National Instruments PCI-6251 User Manual

B-34 | ni.com
Appendix B Timing Diagrams
Count Enable Delay
Table B-29 shows timing for the internal Count Enable signal, as shown in Figure B-41. Count
Enable enables the 32-bit counter to count on the rising edge of the Selected Source signal.
The delays depend on both the synchronization mode and gating mode for the application.
Figure B-45. Count Enable Delays
Table B-28. Selected Source Delays Timing
Time From To Min (ns) Max (ns)
t
3
PFI_i, RTSI_i, PXI_STAR_i, or any
internal signal
Selected
Source
8.0 21.0
20 MHz Timebase Selected
Source
1.5 4.0
100 kHz Timebase Selected
Source
1.5 4.0
80 MHz Timebase Selected
Source
1.0 2.5
PXI_CLK10 Selected
Source
1.0 3.5
t
4
t
4
Selected_Gate
Count_Enable

National Instruments PCI-6251 Specifications

General

Brand	National Instruments
Model	PCI-6251
Category	I/O Systems
Language	English