Measurement systems with large channel counts often require switches to route signals between multiple inputs and outputs. In a new application note, Satellite Test Cell Switch Systems, Precision Filters documents the improvements achieved by upgrading a customer’s manual patch panels to a computer-controlled analog signal switching system. Download the article today.
A large satellite manufacturer sought a replacement for manual patch panels used to control signal flow between hundreds of input and output channels in a test facility. Their existing manual patch system took hours to reconfigure and was prone to faulty connections and damage to the contacts via repeated manipulation. Signals originated from distal areas of the facility, creating ground loops that generated noise in the acquired data with unacceptable DC errors. Verification of switch system connections took days to perform and tight test schedules often meant skipping this important step. To remedy these problems, the customer sought a 768 x 512 solid-state switch matrix to interface sensor based signals with multiple data acquisition, control and other measurement equipment.
The customer selected PFI’s programmable switch matrix system to replace the legacy manual patch panel. The solution incorporates durable high-density solid-state switches in a 3-stage architecture to ensure reduced crosstalk and increased bandwidth over shorter signal paths. Differential input buffers eliminate noise from ground loops and correctly reference the sensor signal to the distant ground reference. System expansion is easily accomplished by adding additional chassis “building blocks”.
A spreadsheet-based graphical user interface (GUI) with intuitive row/column matrix indexing of inputs and outputs is used to control the switch over the Ethernet remote interface. Channel names are easily customized and visually associated with color-coded channel groupings. Multiple switch configurations can be saved and downloaded from the host computer. Configurations can also be saved in CSV format and viewed/edited off-line using standard spreadsheet software.
For documented proof of valid system configuration, quick and easy built-in self-test (BIT) routines are included to measure switch system parametrics (gain, offset, crosstalk, open/short) and verify performance.