Filter
Top Products
USB-1616HS-2 User's Guide Specifications
48
Counters
Counter inputs can be scanned based on an internal programmable timer or an external clock source.
Table 6. Counter specifications
Channels 4 independent
Resolution 32-bit
Input frequency 20 MHz maximum
Input signal range -5 V to 10 V
Input characteristics
10 kΩ pull-up, 200 Ω series resistor, ±15 kV ESD protection
Trigger level TTL
Minimum pulse width 25 ns high, 25 ns low
Debounce times
16 selections from 500 ns to 25.5 ms, positive or negative edge sensitive, glitch
detect mode or debounce mode
Time base accuracy 50 ppm (0 ° to 50 °C)
Counter read pacer Onboard input scan clock, external input scan clock (APR)
Trigger sources and modes See Table 8
Programmable mode Counter
Counter mode options
Totalize, clear on read, rollover, stop at all Fs, 16- or 32-bit, any other channel can
gate the counter
Input sequencer
Analog, digital, and counter inputs can be scanned based on either an internal programmable timer or an
external clock source.
Table 7. Input sequencer specifications
Input scan clock sources: two (see Note 4) Internal, programmable:
Analog channels from 1 µs to 1 s in 20.83 ns steps.
Digital channels and counters from 250 ns to 1 s in 20.83 ns steps.
External. TTL level input (APR):
Analog channels down to 1 µs minimum
Digital channels and counters down to 250 ns minimum
Programmable parameters per scan: Programmable channels (random order), programmable gain
Depth 512 locations
Onboard channel-to-channel scan rate Analog: 1 MHz maximum
Digital: 4 MHz if no analog channels are enabled, 1 MHz with analog
channels enabled
External input scan clock (APR) maximum
rate
Analog: 1.0 MHz
Digital: 4 MHz if no analog channels are enabled, 1 MHz with analog
channels enabled
Clock signal range: Logical zero: 0 V to 0.8 V
Logical one: 2.4 V to 5.0 V
Minimum pulse width 50 ns high, 50 ns low
Note 4: The maximum scan clock rate is the inverse of the minimum scan period. The minimum scan
period is equal to 1 µs times the number of analog channels. If a scan contains only digital
channels, then the minimum scan period is 250 ns.
Some platforms can sustain clock rates up to 83.33 ns.