Counter Interrupt

Asynchronously invokes the function-call subsystem when a counter interrupt occurs on the Q8 data acquisition system.

Library

qctools

Description

The Counter Interrupt block for the Q8 series of I/O cards provides a mechanism for handling asynchronous counter interrupts. Attaching a function-call subsystem to an output causes the function-call subsystem to be executed as soon as the associated counter interrupt occurs. The code executes asychronously from the rest of the model. The timing of its execution is not governed by the sampling period of the system.

	Note that the Asynchronous Interrupt blocks may only be used in Windows if the Q8 Windows driver has been converted to an RTX driver using Convert To RTX in the RTX Properties control panel. One of the Time Base blocks is also required in the model for these blocks to be used.

Block Outputs

CNTROUT

The function-call subsystem attached to this output will execute when the general purpose counter output goes low. The interrupt is edge-triggered. The falling edge is used because the external CNTR_OUT pin is held high when the counter output is disabled. Hence, a falling edge is the most natural transition on which to interrupt the CPU.

Parameters and Dialog Box

Board Number

The board number of the I/O card. If there is only one Q8 board in your system, then the board number should be zero. The second Q8 board in your system is board number 1, etc.