In general, in devices using Windows operating system based on x86, real-time performance is not guaranteed. It is because Windows is not a Real-Time Operating System (RTOS). Users who develop applications in such a Windows environment generally use commercial solutions, RTX and INtime, to have real-time performance. However, when using functions and API for simple real-time processing, a problem of high development cost occurs in terms of cost-effectiveness. The RTiK and the RTiK-MP were developed to improve those problems, but there is a problem with supportability depending on the Windows version. In addition, because of the characteristics and objectives of the weapon system, stability and reliability are more important than the latest software version, and the Products Life Cycle is in maturity are preferred. In the test equipment that checks the function and performance of the main weapon system with subsystems and components, when selecting the Windows operating system, currently, Windows 8 is mainly used in the weapon system rather than the recent Windows 10. However, the previously developed the RTiK+ and the RTiK-MP support real-time processing functions only Windows XP and Windows 7, and it can no longer be used, so the RTiK+ was studied to support higher Windows version.
In this paper, the RTiK+ was implemented in the type of a device driver by controlling the MSR_FSB_FREQ register to generate a timer interrupt independent of Windows in the Windows 8 and providing a real-time period to the user area (ring 3) by re-setting the local APIC count register. In addition, in a mobile device such as a Tablet PC, the operating frequency of the CPU is changed to minimize power consumption for battery life. As a result, the period of the RTiK+ after setting needed period is changed, causing a problem in that real-time performance is not guaranteed. To improve those problems, this paper studies a method to guarantee real-time performance by controlling the MSR_PKG_CST_CONFIG_CONTROL that determines a CPU operating frequency so that the period of controlling C-States does not change.
The highly reliable portable test equipment (PTE) that proves the performance of guided weapon system is equipment that determines the quality of guided missiles before assembling them or conducting experimental like functional test, environmental test, and flight test. The portable test equipment checks the Built-In Test (BIT) and functions of the subsystems and components mounted on the guided weapon system, which is a mainstay, through serial communication such as RS-232C, RS-422, Ethernet and MIL-STD-1553B based on the Windows operating system. In particular, the precision guided weapon system uses highly reliable MIL-STD-1553B communication and performs BC and RT functions of MIL-STD-1553B to transmit/receive data in communication between the portable test equipment and precision guided weapon system. It is of significantly importance to guarantee integrity of data without loss during communication. For this purpose, it is proposed to implant the proposed MIL-STD-1553B communication scheduling algorithm with RTiK+ for Windows 8 to give a real-time processing function in the Windows operating system on the portable test equipment (PTE) based on embedded system, and to use the real-time period provided by RTiK+ when performing the BC and RT functions of MIL-STD-1553B. In this method, double buffers are used because MIL-STD-1553B communication is performed asynchronously when communicating between two devices such as portable test equipment and guided weapon system, resulting in overhead, so the normally interrupt method cannot be applied. Therefore, to solve this problem, a polling method is proposed when the BC of MIL-STD-1553B transmits data in the period provided by RTiK+ and immediately receives the data from the BC. In case of MIL-STD-1553B of fast communication such as a 2ms period, if a malfunction occurs in the period between the transmitting data and the receiving data, the malfunction occurs that overwrites data at same area or takes garbage from the buffer. In this paper, the method of MIL-STD-1553B communication scheduling algorithm using double buffers is proposed to solve it.
In addition, in this paper, RTiK+ is implanted in a Windows 8 on a mobile device like Tablet PC and the various periods such as 0.1ms(max), 1ms, 3ms, 5ms, 10ms, and 25ms(min) needed by MIL-STD-1553B communication of the test equipment are proved and it was satisfied. In addition, it is verified using oscilloscope as hardware measuring method and RDTSC as software measuring method for saving all period of RTiK+ and PASS 3200 for MIL-STD-1553B MT that the proposed RTiK+ is implanted in Windows on test equipment, and the MIL-STD-1553B communication is performed to guaranteed integrity of data during communication even in high-speed communication such as 2ms(max), 5ms, and 10ms(min) without miss rate.
In addition, it shows that RTiK+ can be used as a replacement solution for a third party because RTiK+ seems almost same performance for real-time performance with RTX through evaluation test with the same experimental conditions.