Measurement Computing USB-2408 Series - Manual (Page 29)

USB-2408 Series User's Guide Specifications
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Counter
Table 20. CTR specifications
Parameter Conditions Specification
Pin name CTR0, CTR1
Number of channels 2 channels
Resolution 32-bits
Counter type Event counter
Input type Schmitt trigger, rising edge triggered
Input source CTR0 (pin 44)
CTR1 (pin 42)
Counter read/writes rates
(software paced) Counter read System dependent, 500 reads per second.
Counter write System dependent, 500 writes per second.
Input characteristics Each CTRx input pin 562 kΩ pull-up resistor to +5 V, 10 kΩ series
resistor
Input voltage range ±15 V max
Max input voltage range CTR0,CTR1 relative to AGND
and DGND (Note 7) ±20 V max (power on/off)
Input high voltage 1.3 V min, 2.2 V max
Input low voltage 1.5 V max, 0.6 V min
Schmitt trigger hysteresis 0.4 V min, 1.2 V max
Input bandwidth (–3 dB) 1 MHz
Input capacitance 25 pf
Input leakage current ±120 nA@5 V, ±1.6 mA@±15 V
Input frequency 1 MHz, max
High pulse width 500 ns, min
Low pulse width 500 ns, min
Note 7: DGND pins are recommended for use with counter input pins. The DGND and AGND are common
and are isolated from earth ground.
Memory
Table 21. Memory specifications
EEPROM 4096 bytes isolated micro reserved for sensor configuration
256 bytes USB micro for external application use
Microcontroller
Table 22. Microcontroller specifications
Type One high-performance 8-bit RISC microcontroller with USB interface (non-isolated)
One high-performance 16-bit RISC microcontroller for measurements (isolated)