Measurement Computing PCI-DAS1002 - Manual (Page 21)

PCI-DAS1002 User's Manual Specifications
21
Counters
Table 9. Counter specifications
Parameter Specification
Counter type 82C54
Configuration Two 82C54 devices. 3 down counters per 82C54, 16 bits each
82C54A: Counter 0 - ADC residual
sample counter Source: ADC Clock
Gate: Internal programmable source
Output: End-of-Acquisition interrupt
Counter 1 - ADC pacer lower
divider Source: 10 MHz oscillator
Gate: Tied to counter 2 gate, programmable source
Output: Chained to counter 2 clock
Counter 2 - ADC pacer upper
divider Source: Counter 1 output
Gate: Tied to counter 1 gate, programmable source
Output: ADC pacer clock (if software selected). Available at
user connector.
82C54B: Counter 0 - pretrigger mode Source: ADC clock
Gate: External trigger
Output: End-of-Acquisition interrupt
Counter 0 - user counter 4
(when in non-pretrigger mode) Source: User input at 100-pin connector (CTR4 CLK)
or internal 10 MHz (software selectable)
Gate: User input at 100-pin connector (CTR4 GATE)
Output: Available at 100-pin connector (CTR4 OUT)
Counter 1 - user counter 5 Source: User input at 100-pin connector (CTR5 CLK)
Gate: User input at 100-pin connector (CTR5 GATE)
Output: Available at 100-pin connector (CTR5 OUT)
Counter 2 - user counter 6 Source: User input at 100-pin connector (CTR6 CLK)
Gate: User input at 100-pin connector (CTR6 GATE)
Output: Available at 100-pin connector (CTR6 OUT)
Clock input frequency 10 MHz max
High pulse width (clock input) 30 ns min
Low pulse width (clock input) 50 ns min
Gate width high 50 ns min
Gate width low 50 ns min
Input low voltage 0.8 V max
Input high voltage 2.0 V min
Output low voltage 0.4 V max
Output high voltage 3.0 V min
Crystal oscillator frequency 10 MHz
Frequency accuracy 50 ppm