Справочник Пользователя для Omega OM-USB-1208FS
OM-USB-1208FS User's Guide
Specifications
25
External trigger
Table 12. Digital trigger specifications
Parameter
Conditions
Specification
Trigger source (Note 6)
External Digital
TRIG_IN
Trigger mode
Software selectable
Edge sensitive: user configurable for CMOS compatible
rising or falling edge.
rising or falling edge.
Trigger latency
10 µs max
Trigger pulse width
1 µs min
Input high voltage
4.0 V min, 5.5 V absolute max
Input low voltage
1.0 V max, –0.5 V absolute min
Input leakage current
±1.0 µA
Note 6:
TRIG_IN is a Schmitt trigger input protected with a 1.5 kilohm (kΩ) series resistor.
External clock input/output
Table 13. External clock I/O specifications
Parameter
Conditions
Specification
Pin name
SYNC
Pin type
Bidirectional
Software selectable direction
Output (default)
Outputs internal A/D pacer clock.
Input
Receives A/D pacer clock from external source.
Input clock rate
50 KHz, maximum
Clock pulse width
Input mode
1 µs min
Output mode
5 µs min
Input leakage current
Input mode
±1.0 µA
Input high voltage
4.0 V min, 5.5 V absolute max
Input low voltage
1.0 V max, –0.5 V absolute min
Output high voltage (Note 7)
IOH = -2.5 mA
3.3 V min
No load
3.8 V min
Output low voltage (Note 7)
IOL = 2.5 mA
1.1 V max
No load
0.6 V max
Note 7:
SYNC is a Schmitt trigger input and is over-current protected with a 200 Ω series resistor.
Counter
Table 14. Counter specifications
Pin name (Note 8)
CTR
Counter type
Event counter
Number of channels
1
Input type
TTL, rising edge triggered
Input source
CTR screw terminal
Resolution
32 bits
Schmidt trigger hysteresis
20 mV to 100 mV
Input leakage current
±1 µA
Maximum input frequency
1 MHz
High pulse width
500 ns min
Low pulse width
500 ns min
Input high voltage
4.0 V min, 5.5 V absolute max