Measurement Computing USB-TEMP-AI - Manual (Page 26)

USB-TEMP-AI User's Guide Specifications
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Note 19: All ground pins are common and are isolated from earth ground. If a connection is made to earth
ground when using both digital I/O and conductive thermocouples, the thermocouples are no longer
isolated. In this case, thermocouples must not be connected to any conductive surfaces that may be
referenced to earth ground.
Counter
Table 16. CTR I/O specifications
Parameter Specification
Pin name CTR
Number of channels 1
Resolution 32-bits
Counter type Event counter
Input type TTL, rising edge triggered
Input source CTR screw terminal
Counter read/writes rates
(software paced) Counter read: System dependent, 33 to 1000 reads per second.
Counter write: System dependent, 33 to 1000 reads per second.
Schmidt trigger hysteresis 20 mV to 100 mV
Input leakage current ±1.0 µA typ
Input frequency 1 MHz max
High pulse width 500 nS min
Low pulse width 500 ns 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
Note 20: All ground pins are common and are isolated from earth ground. If a connection is made to earth
ground with both the counter (CTR) and conductive thermocouples, the thermocouples are no longer
isolated. In this case, thermocouples must not be connected to any conductive surfaces that may be
referenced to earth ground.
Memory
Table 17. Memory specifications
Parameter Specification
EEPROM 1,024 bytes isolated micro reserved for sensor configuration
256 bytes USB micro for external application use
Microcontroller
Table 18. Microcontroller specifications
Parameter Specification
Type Two high-performance 8-bit RISC microcontrollers
USB +5V voltage
Table 19. USB +5V voltage specifications
Parameter Specification
USB +5V (VBUS) input voltage
range 4.75 V min to 5.25 V max