Measurement Specialties USB-1616HS-2 manual Digital input/output specifications

USB-1616HS-2 User's Guide Specifications

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
	ƒ	Asynchronous, under program control at any time relative to input scanning
	ƒ	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:
	ƒ	Onboard output scan clock, independent of input scan clock
	ƒ	Onboard input scan clock
	ƒ	External output scan clock (DPR), independent of external input scan clock
		(APR)
	ƒ	External input scan clock (APR)
Digital input trigger sources and	See Table 8
modes
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.

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