Measurement Computing PC104-DAS16JR/12 - Manual (Page 27)

Counter section
Counter type 82C54
Configuration 3 down-counters, 16 bits each
Counter 0 - Independent user counter
Source: Programmable (external or
100 kHz internal source)
Gate: Available at connector (DIn 2)
Output: Available at connector (Ctr 0
Out)
Counter 1 - ADC Pacer Lower Divider
Source: Jumper-selectable 1/10 MHz
Gate:
Tied to Counter 2 gate, can be
program-enabled at user
connector (DIn 0 / Trigger).
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: Programmable as ADC Pacer
clock, hardwired to user
connector (Ctr 2 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 0.8V max
Input high voltage 2.0V min
Output low voltage 0.4V max
Output high voltage 3.0V min
Crystal oscillator
Frequency 10 MHz
Frequency accuracy 100 ppm
Environmental
Operating temperature range 0 to 50°C
Storage temperature range
−
40 to 100°C
Humidity 0 to 90% non-condensing
23