Timing i/o – National Instruments PCI-1200 User Manual
Page 76

Appendix A
Specifications
A-8
© National Instruments Corporation
Power-on state ........................................All ports mode 0 input
Protection................................................–0.5 to 5.5 V powered on,
±0.5 V powered off
Data transfers ..........................................Interrupts, programmed I/O
Timing I/O
Number of channels................................3 counter/timers
Protection................................................–0.5 to 5.5 V powered on,
±0.5 V powered off
Resolution
Counter/timers .................................16 bits
Compatibility ..........................................TTL
Base clock available ...............................2 MHz
Base clock accuracy................................±50 ppm max
Max source frequency.............................8 MHz
Min source pulse duration ......................125 ns
Min gate pulse duration ..........................50 ns
Digital logic levels
Output low voltage
(I
OUT
= 2.5 mA)
—
0.4 V
Output high voltage
(I
OUT
= –40
µA)
(I
OUT
= –2.5 mA)
4.2 V
3.7 V
—
—
Level
Min
Max
Input low voltage
–0.3 V
0.8 V
Input high voltage
2.2 V
5.3 V