TIC Expansion Module (TEM) NI Alliance Partner

TIC expansion module as a plug-in module for desktop SCANFLEX TAP transceivers 2/4/6/7/8S and SCANBOOSTER NI alliance partners

PXI

PXI uses the PCI interface on the backplane, most of which operate at 33MHz and 32-bit wide to provide BW sufficient for its intended application. There are only three types of slots:

• The system slot is used to accept the controller or the remote interface of the controller.

• The star trigger slot can accept peripheral modules or star trigger controllers and drive modules that use the star trigger function. The star trigger socket can be used as a normal peripheral socket. Because the trigger model used is usually based on IVI (software), it is not common to use a trigger system on a PXI switch module.

• Peripheral slot, accept any peripheral PXI module.

The backplane is shared between the modules, and is displayed with the devices on the bus as a set of bus numbers (corresponding to each segment of the PCI bus), usually numbered from 15 downward. All devices in a particular bus number share the same 32-bit PCI bus segment. The standard limits the number of buses to 256.

PXI Express

The PXI Express (PXIe) chassis uses the PCI Express serial interface to connect to peripheral devices from its system slot. The system slot is not compatible with PXI, so you need to use a controller or PCIe interface with a sufficient number of PCIe connections to support peripheral devices. The use of the serial interface improves the available BW of the peripheral, because in principle it is not a shared BW-each peripheral gets one or more serial connections with a serial rate of 2.5Gb/s (GEN1). Since PCIe is a point-to-point connection system, each connection is defined as a bus number and device 0 (other devices are not displayed on this slot). Like PCI, it has a 256 bus limit. Therefore, the maximum number of modules is lower than PXI.

Using PXI Express does not guarantee a faster system speed. The most common system speed bottleneck has nothing to do with the backplane speed, but its speed advantage can be seen in modules that receive or transmit large amounts of data.

PXI Express mechanical and electrical interfaces are different from PXI. In order to take full advantage of the fast PCI Express channel, the chassis usually contains a mix of PXI and PXI Express slots (hybrid chassis). Therefore, the chassis can specify many slot types. Generally, the slot is defined as:

• Controller slot. Only controllers designed for PXIe and hybrid chassis are accepted.

• PXI Express slot. Only accept PXI Express modules with relatively few types available.

• Hybrid slot. They can accept PXI Express or PXI modules. It has two sets of connectors, but the second PXI connector is shortened to allow for PXIe connectors. All Pickering switch modules are compatible with Hybrid slots.

• Traditional slot, it only accepts PXI modules.

• Trigger the slot, which can only be occupied by modules designed to fill the slot, so it is not suitable for "normal" peripheral modules. For this reason, some chassis do not include timing slots.

PXI Express chassis also differ in the number of PCIe channels supported in each channel. This is transparent to users, but for high-speed applications, there is a considerable advantage in ensuring that certain PXIe slots have a large number of PCIe channels, because this is also the main reason for specifying PCIe-enabled chassis.

There are other electrical differences, especially in power sources. PXI Express lacks 5V and -12 V power supplies. The 5V power supply is a special problem, because the most commonly used relays have 5V coils-and are stored in the distribution channel, so it is easiest to get service support.

The vast majority of peripheral devices are PXI rather than PXI Express.