Product Details

PCI/PXI M series and PCI Express/PXI Express X series NILABVIEWNIDAQ

PCI and PCIe use the same basic process to "discover" PXI(e) modules based on these two standards. PCI(e) modules are identified by bus number and device number. In PCI, there can be up to 16 devices on the bus (actually PXI 8 devices, including bridges at each end), indicating the bus number of the bus segment and the bus number on the bus segment The equipment of each module. In PCIe, the situation is slightly different because it is a point-to-point system (rather than a multipoint system like PCI), and each module has its own bus number. In both cases, PCI is limited to 256 buses, which must include the bus inside the controller and any bridges or virtual buses associated with it. Therefore, for PCIe, the theoretical maximum number of modules that can be connected is equivalent to PCI, but it is still quite large compared to the number of buses in a typical single chassis.

Some PCs also seem to have BIOS issues related to enumerating long-chain bus connections, so PXIe chassis vendors may strongly recommend the use of tested embedded or remote controllers and provide a list of these models. Assuming that because a certain controller model comes from a specific manufacturer, then all the controllers of that manufacturer can work normally. This is unsafe and certainly not the case. This problem seems to be due to the fact that PCs generally do not expect a large number of PCIe buses, and there is a conflict between supporting large bus numbers and the user's need for fast startup time.

X series data acquisition (DAQ) equipment includes 32 analog input channels (AI), 4 analog output channels (AO), 48-bit digital I/O lines and 4 counters. The sampling range of X series data acquisition (DAQ) devices is from 250 kS/s rate multi-channel switching AI to 2 MS/s rate simultaneous sampling AI. Simultaneous sampling X-series data acquisition equipment integrates up to 16 A/D converters in one device, and each channel can reach a rate of 2 MS/s. Therefore, engineers can sample all analog input channels at a high sampling rate while avoiding Phase shift. But also because of this, synchronizing X series devices will need to transfer a large amount of data back to the host PC, the data throughput will reach 64MB/s, plus the attached AO channel, digital I/O and counter operations, the total data throughput of a single device The amount will reach 100MB/s, which is actually the maximum value of the PCI bus. Therefore, the X series capture card chooses to use the high data throughput PCI Express bus.

PCI Express offers many advantages in data acquisition applications, including a dedicated bandwidth of up to 250 MB/s in each direction for each device. Users can use extra bandwidth to collect more analog, digital, and counter data; and by using a dedicated bus, engineers can more easily expand their systems to include multiple data collection devices. The new X-series devices integrate the original PCI Express interface, thereby providing a PCI Express bandwidth of 250 MB/sec, rather than a PCI-to-PCI Express bridge interface. That would limit the device bandwidth to the PCI bus bandwidth. These devices also optimize low-latency I/O, thereby improving the performance of control and single point applications.