How fast interrupt response time directly reflects the speed of a process

3.1 test environment and method
How fast interrupt response time directly reflects the speed of a process: laptop battery in the user layer user process through the system call pulse data is written in the core layer of real-time driver data buffer queue, the next DDA interrupt request comes, The buffer of the control chip of the interrupt service routine to the operation of the pulse data is written in the data buffer queue the triaxial position control card, driving the robot body to be operated. Therefore, we will start calling the user process of the user layer system calls the moment of the transmission pulse data as the test start time.

So in this case, in order to ensure the real-time nature of the movement of the robot, using the advantage of RT-Linux reflected. If in the case of NIC intervention tested under standard Linux interrupt processing time than RT. Under Linux would be far more longer.under a DDA interrupt request arrives, the DDA interrupt service routine to write data to the the triaxial position control card Actions control chip buffer in order to drive the robot body running time as the moment of the end of the test. Figure 3 reflects the above-mentioned process.The actual use of the real-time robot controller, robot run very stable and can meet the needs of real-time control.

3.2 Test results
The DDA cycle were set 8,12,16,24 ms four situations were tested with the results as shown in Table 1, through calculation, can be drawn.
Table 1 under low load D DA interrupt response processing time test resultsVisible at low load measurement time RT-Linux than under Linux 0.5-0.6ms faster, laptop battery that can really improve the real-time performance of the system using RT-Linux systems. Here are a few caveats:Used to test industrial control computer hardware configuration IntelPentium (clockl20MHz) RAM64MB; The server software RedHatLinux6.0 (kernel version 2.2.5 l5), RT-Linux version number 2.2; network environment l0/100M adaptive network card.

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