Measurement Computing USB-TC - Manual (Page 17)

USB-TC User's Guide Specifications
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Note 6: The analog inputs are configured to run continuously. Each channel is sampled twice per second.
The maximum latency between when a sample is acquired and the temperature data is provided by
the USB unit is approximately 0.5 seconds.
Digital input/output
Table 5. Digital input/output specifications
Parameter Specification
Digital type CMOS
Number of I/O 8 (DIO0 through DIO7)
Configuration Independently configured for input or output.
Power on reset is input mode.
Pull-up/pull-down configuration All pins pulled up to +5 V via 47 K resistors (default). Pull-down to ground (GND)
also available.
Digital I/O transfer rate
(software paced)  Digital input: 50 port reads or single bit reads per second, typ
 Digital output: 100 port writes or single bit writes per second, typ
Input high voltage 2.0 V min, 5.5 V absolute max
Input low voltage 0.8 V max, –0.5 V absolute min
Output low voltage
(IOL = 2.5 mA) 0.7 V max
Output high voltage
(IOH = –2.5 mA) 3.8 V min
Note 7: All ground pins are isolated from earth ground. If a connection is made to earth ground when using
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.
Memory
Table 6. Memory specifications
Parameter Specification
EEPROM 1,024 bytes isolated micro reserved for sensor configuration
256 bytes USB micro for external application use
Microcontroller
Table 7. Microcontroller specifications
Parameter Specification
Type Two high performance 8-bit RISC microcontrollers
USB +5V voltage
Table 8. USB +5V voltage specifications
Parameter Specification
USB +5V (VBUS) input
voltage range 4.75 V min to 5.25 V max