Bus analyzers are used to monitor and check the performance of a system bus. In general bus analyzers are able to offer real-time protocol check, bus performance statistics, monitoring of latencies, throughput, and data transfer in real time. These devices are available in a number of form factors including computer boards, modules, or separate portable units.
Bus exercisers can emulate and force behavior of buses so that their performance can be tested and charted. These tests may take the form of worst-case scenario simulations to better understand how failure could disrupt the entire network system. Bus exercisers can generate high throughput data, and disturb the system by introducing forced errors while simultaneously measuring the system response to these events. Like bus analyzers, bus exercisers are available in a number of form factors including computer boards, modules, or separate portable units.
Bus analyzers and bus exercisers are available as separate devices, although some multi-function devices are available that can perform both functions. Each analyzer or exerciser (or multi-function unit for that matter), however, is attuned to a specific network protocol. These protocols (such as ISA / EISA, PCI / PCI-X, SCSI, VME / VXI, and USB, among others) dictate the manner in which all of the components and peripherals with a network communicate with each other.
The speed at which bus analyzers and bus exercisers perform their associated functions are measured in terms of data capture rate or transfer rate, respectively. These measurements, calculated in MBps (mega bytes per second), are determined by multiplying the clock rate of the bus (analyzer or exerciser) by the bus width and dividing by 8 (8 bits per byte). For example, an analyzer with a clock speed of 33 MHz and bus width of 64 bits has a maximum data capture rate of 264 MBps.