USB DAQ with 28 digital I/O, drive capability for solid-state relays (64mA sink) , one 32-bits counter input (Maximum input frequency: 12 MHz). Includes USB cable. USB Low Cost Digital I/O Module with 28 programmable digital I/O lines with high drive capability to drive solid state relays and one 32-bit counter/timer. These 28 lines are organized as three 8-bit ports and one 4-bit port. These ports can be configured as input, output, or any combination required. This module offers high-drive capability that sinks 64 mA and sources 15 mA for driving sold-state relays.
Counter/Timer Subsystem
The counter/timer subsystem on these modules can be run by an internal or external clock source.
- Internal clock – Through software the user can specify the frequency at which to pace the counter/ timer operation. This frequency can range from 4 Hz to 12 MHz
- External clock – The user connects an external clock source with a maximum frequency of 6 MHz and then uses a clock divider to specify the actual frequency to pace the counter/timer operation. This is useful when the user wants to pace counter/timer operations at rates not available with the internal clock or if uneven intervals are required.
The subsystem supports four separate operating modes:
- Event counting – This mode is used to count the number of falling edges that occur. The user can count up to 4,294,967,296 events before the counter rolls over to 0 and starts counting again.
- Frequency measurement – This mode allows the user to determine the frequency of the clock input.
- Edge-to-edge measurement – This mode allows the user to measure the time interval between a specified start edge and a specified stop edge. The user can measure the pulse width, the period, and the frequency of the signal.
- Rate generation – This mode allows users to generate square waves with an output frequency from 4 Hz to 12 MHz.
