Signal integrity tests often display results in an "eye" diagram that relates signal timing to signal levels. When testing a communication channel, for example, test equipment compares an eye diagram of acquired data with an eye template defined by standards organizations. When you perform tests on digital devices, similar eye diagrams can provide information about signal integrity.
Stand-alone instruments and instrument cards can adjust voltages and timing to perform signal-integrity measurements in digital systems. But the situation gets complex when tests involve hundreds of real-world digital signals.
You might not think of a logic analyzer as a signal-integrity tester. The state/timing modules for the 16700 family of logic analyzers from Agilent Technologies, however, provide built-in capability to construct such eye diagrams. The modules vary signal thresholds (windows) to monitor signal levels at specific times. The logic analyzer simultaneously measures hundreds of signals to build up signal-integrity information for each channel.