1. STD bus
The STD bus was first invented by Pro-Log Company as an industrial standard in 1978. It was formulated by STDGM as the STD80 specification, and was subsequently approved as the international standard lEEE961. The STD bus industrial computer is an industrial computer. The 16-bit bus performance of the STD bus meets the requirements of embedded and real-time applications, especially its small board size, vertically placed passive backplane in-line structure, and rich industrial νoOEM templates , low cost, low power consumption, extended temperature range, reliability and good maintainability design make it widely used in the field of industrial automation where space and power consumption are strictly limited and reliability requirements are high.
The STD bus industrial computer adopts single-chip computer technology, which can continue to improve the performance of the All-In-One CPU board without being limited by the size of the small board.
Since the STD bus came out in 1978, the STD bus industrial computer has been proven to be the main force for the realization of industrial control.
With the advancement of technology, the original STD80 standard recognized by industrial users has been difficult to meet the requirements. In September 1991, STD32MG released version 1.0 of the STD32 specification. STD32 has 32-bit data width and 32-bit addressing capability, and is an industrial high-end computer. The STD32 bus is compatible with the STD80 specification, and the products can be interoperable.
The strength of the bus does not lie in how advanced it is in theory, but in the richness of the number and types of OEM templates developed for this bus. The STD32 bus industrial computer is supported by many OEM manufacturers. It can not only use the rich STD bus νo templates that have been put on the market, but also the STD32 bus I/O templates that are continuously pushed to the market by STD32 product manufacturers, and other PC-compatible Compatible resources form an industrial control system. The STD32 bus supports hot switching and multi-master systems, meeting the requirements of industrial control redundancy design.
While the STD32 bus retains the characteristics of a simple control bus, it adopts today's advanced technology to design OEM products, such as 80486 and Pentium series processor technology.
The actual commercial operation on site shows that the STD industrial control system is relatively stable, but its architecture still has deficiencies. The STD industrial control board uses "golden fingers" to pull out and plug in, which occasionally causes the copper anchor near the edge plug of the printed board to break or the bus contact is poor. The analog input measurement lines and I/O signal lines are connected by front-end flat cables, so that the reliability of the entire system operation is potentially threatened.
2. AT96 bus
In order to apply ISA bus PCs in harsh industrial environments, the AT96 bus European card standard (IEEE996) was initiated by the German SIEMENS company in 1994, and has been popularized and applied in Europe. AT96 bus = ISA bus electrical specification bucket 96-core pinhole connector + European card specification (IEC297 Zhuangtian E 1011.1) 0 AT96 bus industrial computer eliminates the edge golden finger connection between the templates, and has the ability to resist strong vibration and impact; its 16 Bit data bus, 24-bit addressing capability, high reliability and good maintainability, more suitable for application in harsh industrial environments. In foreign countries, the AT96 bus industrial computer is relatively complete, including 80386, 80486 products, and Pentium series products, which support high-speed Ethernet network interfaces. A new generation of embedded APCI5 series industrial computer developed by a company in Beijing using the AT96 bus supports both the AT96 bus and the Coract PCI bus, so that the standard AT96 bus and CPCI bus templates can be inserted into the AT96 bus industrial computer at the same time to meet the needs of embedded real-time Industrial control systems require different performance industrial computers. Such as APCI5094 industrial computer, 486DX4 (66 ~ 133MHz) CPU, AT96 and CPCI bus, cancel gold finger and flat cable connector, field I/O signal is served from the rear side to the port through elastic connection, with high performance and high reliability, Can be used on sports targets.
3. VME bus
The VME bus industrial computer has always been the preferred model for many embedded industrial applications. In 1981, Mostek, Motorola, Philip and Signetics invented the VME bus. Since then, the VME bus industrial computer has been widely used in image processing, industrial control, real-time processing and military communication. In 1987, the VME bus was approved as an international standard IEEE 1014-1987. The VME bus interface is two 96-core pinhole connectors PI and P2 (6U Eurocard), and the concave outer two rows of pins are customized by the user to meet the special requirements of the user. The data width of the VME bus is 32 bits, and the maximum bus rate is 40MB/s.
The new standard VM 4 (ANSWITA1-1994) in 1996 increased the bus data width to 64 bits, and the maximum data transfer rate was 80MB/s. The VM bus specification formulated by FORCE COMPUTERS also raised the bus rate to 320MB/s.
The VME bus industrial computer is a real-time control platform, and most of them run real-time operating systems, such as UNIX, VxWorks, PSOS, VRTX, PDOS, LynOS, and VME C. OS manufacturers provide special software development tools to develop applications.
VME bus OEM products are supported by many manufacturers, mainly using Motorola's 68K series microprocessors, such as 25Mt33M's 68060. Now more and more manufacturers of VME bus SBC begin to adopt microprocessors produced by Intel Corporation and AMD Corporation.
It can be seen from the operating systems of the VXI bus and VME bus industrial computers: VXI bus industrial computer manufacturers hope to be compatible with the rich and cheap application software development kits, peripherals and driver software provided by the mainstream computer market, while the VME bus can only Work with dedicated development environments and peripherals provided by OS manufacturers or third-party partners.
