Appendix A Specifications
© National Instruments Corporation A-5 Lab-PC+ User Manual
Differential nonlinearity (DNL) in a D/A system is a measure of deviation of code width from
1 LSB. In this case, code width is the difference between the analog values produced by
consecutive digital codes. A specification of ±1 LSB differential nonlinearity ensures that the
code width is always greater than 0 LSBs (guaranteeing monotonicity) and is always less than
2 LSBs.
Digital I/ONumber of channels ...................................... 24
Compatibility ................................................ TTL
Digital logic levels ........................................ Level Min Max
Input low voltage
Input high voltage
Input low current
(Vin = 0.8 V)
Input high current
(Vin = 2.2 V)
-0.3 V
2.2 V
-
-
0.8 V
5.3 V
-1.0 µA
1.0 µA
Output low voltage
(Iout = 2.5 mA)
Output high voltage
(Iout = -2.5 mA)
-
3.7 V
0.4 V
-
Darlington drive output current (Ports B and C only)
(REXT = 700 Ω, VEXT = 1.7 V)................ ±2.5 mA min, ±4 mA max
Handshaking.................................................. 3-wire (requires 1 port)
Power-on state............................................... Configured as input
Data transfers ................................................ Interrupt, programmed I/O
Timing I/ONumber of channels ...................................... 3 counter/timers
Resolution ..................................................... 16 bits
Compatibility ................................................ TTL, gate and source pulled high with
4.7 kΩ resistors
Base clocks available .................................... 2 MHz
Base clock accuracy ...................................... 0.01%
Max source frequency................................... 8 MHz
Min source pulse duration............................. 60 ns
Min gate pulse duration................................. 50 ns
Data transfers ................................................ Programmed I/O