Digital Input/Output; External Trigger - Measurement Computing USB-1608G User Manual

USB-1608G User's Guide

Digital input/output

Parameter
Digital type
Number of I/O
Configuration
Pull-up configuration
Digital I/O transfer rate
(system-paced)
Input high voltage
Input low voltage
Output high voltage
Output low voltage
Output current

External trigger

Parameter
Trigger source
Trigger mode
Trigger latency
Trigger pulse width
Input type
Schmitt trigger hysteresis
Input high voltage
Input low voltage
Table 6. Digital I/O specifications
Specification
CMOS
8
Each bit may be configured as input (power on default) or output
The port has 47 kΩ resistors configurable as pull-ups or pull-downs (default) via
internal jumper (W1).
33 to 8000 port reads/writes or single bit reads/writes per second typ,
system dependent.
2.0 V min
5.5 V absolute max
0.8 V max
–0.5 V absolute min
0 V recommended min
4.4 V min (IOH = –50 µA)
3.76 V min (IOH = –2.5 mA)
0.1 V max (IOL = 50 µA)
0.44 V max (IOL = 2.5 mA)
±2.5 mA max
Table 7. External trigger specifications
Specification
TRIG input
Software programmable for edge or level sensitive, rising or falling edge, high or low
level. Power on default is edge sensitive, rising edge.
1 µs + 1 clock cycle max
100 ns min
Schmitt trigger, 33 Ω series resistor and 49.9 kΩ pull-down to ground
0.4 V to 1.2 V
2.2 V min
5.5 V absolute max
1.5 V max
–0.5 V absolute min
0 V recommended min
18
Specifications