Measurement Computing USB-1616HS-2, Руководство пользователя, Страница: 47 / 54

USB-1616HS-2 User's Guide Specifications
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Digital input/output
Table 5. Digital input/output specifications
Number of I/O 24
Ports Three banks of eight.
Each port is programmable as input or output
Input scanning modes Two programmable

Asynchronous, under program control at any time relative to input scanning

Synchronous with input scanning
Input characteristics 220 Ω series resistors, 20 pF to common
Logic keeper circuit Holds the logic value to 0 or 1 when there is no external driver
Input protection ±15 kV ESD clamp diodes parallel
Input high +2.0 V to +5.0 V
Input low 0 to 0.8 V
Output high >2.0 V
Output low <0.8 V
Output current Output 1.0 mA per pin
Sourcing more current may require a TR-2U power supply.
Digital input pacing Onboard input scan clock, external input scan clock (APR)
Digital output pacing Four programmable sources:

Onboard output scan clock, independent of input scan clock

Onboard input scan clock

External output scan clock (DPR), independent of external input scan clock
(APR)

External input scan clock (APR)
Digital input trigger sources and
modes See Table 8
Digital output trigger sources Start of input scan
Data transfer DMA
Sampling/update rate 4 MHz maximum (rates up to 12 MHz are sustainable on some platforms)
Pattern generation output Two of the 8-bit ports can be configured for 16-bit pattern generation. The pattern
can also be updated synchronously with an acquisition at up to 4 MHz.