Application of the hottest PXI platform in electro

The application of PXI platform in electronic manufacturing

preface

with the evolution of technology and the change of market demand, the methods of electronic manufacturing and testing also change. In the 21st century, people's requirements for product technology to bring a certain error to the intensity comparison, as well as the shortening of product life cycle and the pressure of price, have made electronic manufacturers have to think about whether there is another test platform that can be more competitive than the traditional PC, GPIB or VXI based test platform

this paper will briefly introduce the needs of electronic manufacturing test platform, and discuss how the new PXI platform can meet the application of price sensitive and mass production demand from one or two cases in the electronic manufacturing industry, so that readers can better understand the characteristics and advantages of PXI as a production test platform

demand for production test platform

when it is necessary to set up a new production test platform, we should rethink the demand for production test platform from some specific elements, which include the following points

1. System area

the most common worry of a large number of electronic manufacturers or OEM factories is that it is reported that how to achieve higher production capacity in a limited space when bicycles will be launched in June 2017, that is, how to produce more products in the same land? Of course, most of the factory space is occupied by production equipment, but it cannot be denied that a variety of testing equipment will also be a major consideration in space. Generally, when considering the factor of reducing the production space, especially the area of the test system, test engineers often adopt modular or card based systems, such as PC, VXI or PXI platforms. The following table provides readers with a comparison of the functional density of VXI and PXI platforms

the height of the chassis on the shelf of the system can use the function density of expansion slots (the number of expansion slots divided by the chassis height) VXI, C size 9u121.3pxi, 6u9u13 ~ 191.4 ~ 2.1pxi, 3u5u6 ~ 171.2 ~ 3.2

pxi system configuration to provide a higher function density ratio, so it can provide a denser test system. However, if the user's system needs many additional GPIB instruments and equipment, the advantages of PXI in space and price are not easy to show. However, compared with traditional PC/PCI based system or VXI system, PXI platform still provides test engineers with more flexible options

2. Test module

for the production test of module products, the test module will be another factor that will be considered when selecting the platform. General requirements for test modules are:

- reliable mechanism interface and connectors

- diversification of connectors between receivers and modules

- integrity between modules and test system platforms

at present, some manufacturers have provided PXI systems with modules and receivers, most of which are 3U PXI sizes. However, when integrating the receiver interface with the PXI platform, the biggest challenge is to connect the i/o of the instrument and the test system. For example, for some current high-density testing applications, SCSI type connectors are the most commonly used. It is not difficult to make matching cables for the first industrialized base components based on graphene materials and utilization in China. However, if the receiver interface is to be placed on the PXI system, a more reliable and flexible architecture will be required, and the difficulty will be relatively increased. In general, the consideration of i/o will be an important indicator for selecting a specific receiver or fixture now or in the future

3. System controller

system controller has external and embedded options. Most of the test systems use external system controllers, such as desktop computers. The advantages of using external system controller are as follows:

- it does not occupy the number of VXI or PXI host slots, and more peripheral slots can be provided for instruments and equipment or switchers

- simplify online management with computer peripherals

- desktop computers have competitive advantages in price

- system functions are easy to upgrade

when using external controllers to connect PXI chassis, how to maintain the high-speed transmission speed of PCI bus, and at the same time must have the characteristics of software transparency, just like the bridge on another PCI bus? The extension kit of PCI bus plays a very important role at this time. However, when space is limited or in the special application of data acquisition/process control, using embedded or single board computer in modular system will be a better choice

4. Instrument and signal switcher

there is no doubt that traditional instruments can provide the most extensive functions and suppliers, but limited by the transmission speed of GPIB bus, the requirements for the test function of the instrument are usually more than the test speed. Generally speaking, manufacturers choose platforms such as VXI or PXI as functional test systems, mostly because they are modular and develop a class of photoinduced valence tautomeric compounds with room temperature magneto-optical effect, high-density instrument integration and high-speed data transmission speed. In addition to the evaluation and consideration of the instrument, the signal switcher will be another key point to be considered by the system designer, especially when the user's system needs a considerable signal switcher or even another chassis to handle the signal switching, how to choose the appropriate platform specification will affect the user's system size and price

Application of PXI platform in electronic manufacturing

for many test departments, how to build a test system that can meet the existing functional requirements and has future scalability is of concern and interest to most test engineers. Generally speaking, the architecture of electronic manufacturing test system can be divided into several parts by the following figure. The first part is the hardware architecture, including system platform (3U or 6U), system controller (external desktop computer, which needs to be equipped with pci/pxi extension kit to connect PXI system chassis or embedded PXI controller), test instrument (independent instrument or PXI modular) and switcher. The second part is the software driver. The hardware needs to provide drivers that can support labview/vb/vc/daqbench/pnp and so on. The third part is the test fixture connecting the object to be tested

take the Bluetooth module, which has been controversial in recent years, as an example. From the perspective of function, the Bluetooth module is quite convenient and helpful for personal communication or the connection of peripheral devices. However, due to its high test cost, its price cannot be reduced to the range that consumers think is reasonable, so it cannot be widely promoted to many consumer goods. However, with the production of more cost-effective testing methods and platforms, and the reduction of production and testing costs of Bluetooth modules, Bluetooth modules will have new development opportunities. A set of Bluetooth module test system based on PXI platform usually includes an industrial computer with GPIB adapter card to control external instruments and equipment, a PCI interface extension card to extend PCI bus signals to PXI platform, a PCI interface extension module in PXI chassis, one to two RF switching modules to do signal switching and a/d, and d/a modules to do data acquisition, It is composed of multiple isolation boxes with modules. In the whole test system, the more expensive RF test instrument should be external, but the application of this architecture can increase the utilization rate of external instruments and achieve the purpose of reducing costs

conclusion

pxi platform is undoubtedly a new choice for mass-produced electronic manufacturing test systems because it combines the advantages of open and efficient PCI bus, CompactPCI's robust structural performance and high-density integration