External Trigger; External Clock Input/Output - Measurement Computing USB-1208FS User Manual

USB-1208FS User's Guide

External trigger

Parameter
Trigger source (Note 6)
Trigger mode
Trigger latency
Trigger pulse width
Input high voltage
Input low voltage
Input leakage current
TRIG_IN is a Schmitt trigger input protected with a 1.5 kilohm (kΩ) series resistor.
Note 6:

External clock input/output

Parameter
Pin name
Pin type
Software selectable direction
Input clock rate
Clock pulse width
Input leakage current
Input high voltage
Input low voltage
Output high voltage (Note 7)
Output low voltage (Note 7)
SYNC is a Schmitt trigger input and is over-current protected with a 200 Ω series resistor.
Note 7:
Table 12. Digital trigger specifications
Conditions Specification
External Digital TRIG_IN
Software selectable
Edge sensitive: user configurable for CMOS compatible
rising or falling edge.
10 µs max
1 µs min
4.0 V min, 5.5 V absolute max
1.0 V max, –0.5 V absolute min
±1.0 µA
Table 13. External clock I/O specifications
Conditions Specification
SYNC
Bidirectional
Output (default) Outputs internal A/D pacer clock.
Input Receives A/D pacer clock from external source.
50 KHz, maximum
Input mode 1 µs min
Output mode 5 µs min
Input mode ±1.0 µA
4.0 V min, 5.5 V absolute max
1.0 V max, –0.5 V absolute min
IOH = -2.5 mA 3.3 V min
No load 3.8 V min
IOL = 2.5 mA 1.1 V max
No load 0.6 V max
28
Specifications