The N4915A-005 serial bus switch is designed for high speed serial bus applications such as for example Serial-ATA, PCI Express and others. It can switch very fast one source between two sinks or one sink between two sources while having a low effect on signal integrity.
Integrates Into Automated Test Setups
External trigger capabilities allow to remote control the switch. Test equipment with integrated sequencing capabilities (such as e.g. the J-BERT N4903A) can control the switch position as part of a pattern sequence. Furthermore setups with multiple channels (such as e.g. the Pulse Pattern Generator 81134A or the ParBERT 81250 systems) can dedicate a data channel to control the switch.
Application in Serial-ATA
In Serial-ATA receiver compliance testing different tools are needed for turning on the test mode and for performing the actual test. Without a serial bus switch this requires a change of cables as part of the test procedure.
Changing cables is certainly undesired. Especially in automated test setups it consumes additional time and labor. Also in order to avoid connectivity errors and preserving mechanically sensitive test fixtures changing cables should be avoided.
Besides that the Serial-ATA setup also benefits from the fast switching time. Products under test that do not support disconnect during the test mode wont detect a signal loss while being switched between test tools.
Therefore the N5990A test automation software for Serial-ATA integrates remote controls capabilities for two switch devices.