Digital Input/Output; External Trigger; Counter - Measurement Computing USB-1208LS User Manual

USB-1208LS User's Guide

Digital input/output

Parameter
Digital type
Number of I/O
Configuration
Pull up/pull-down configuration
Input high voltage
Input low voltage
Output high voltage (IOH = –2.5 mA)
Output low voltage (IOL = 2.5 mA)

External trigger

Parameter
Trigger source (Note 4)
Trigger mode
Trigger latency
Trigger pulse width
Input high voltage
Input low voltage
Input leakage current
TRIG_IN is protected with a 1.5 kΩ series resistor.
Note 4:

Counter

Parameter
Counter type
Number of channels
Input source
Input type
Resolution
Schmidt trigger hysteresis
Input leakage current
Maximum input frequency
High pulse width
Low pulse width
Input low voltage
Input high voltage
Table 7. DIO specifications
Specification
82C55
16 (Port A0 through A7, Port B0 through B7
2 banks of 8
All pins pulled up to Vs through 47 kΩ resistors (default). Positions
available for pull down to ground. Hardware-selectable through 0 Ω
resistors as a factory option.
2.0 V min, 5.5 V absolute max
0.8 V max, –0.5 V absolute min
3.0 V min
0.4 V max
Table 8. Trigger input specifications
Conditions
External digital
Software-selectable
Burst
Burst
Table 9. Counter specifications
Specification
Event counter
1
CTR screw terminal
TTL, rising-edge triggered
32 bits
20 mV to 100 mV
±1 µA
1 MHz
500 ns min
500 ns min
0 V min, 1.0 V max
4.0 V min, 15.0 V max
20
Specifications
Specification
TRIG_IN
Level sensitive: user configurable for
TTL level high or low input.
25 µs min, 50 µs max
40 µs min
3.0 V min, 15.0 V absolute max
0.8 V max
±1.0 µA