The BNC-2111 helps you connect to compatible NI data acquisition devices for testing and debugging. This terminal block includes 24 BNC connectors for 16 single-ended analog input signals, two analog output signals, five digital I/O / programmable function input (PFI) signals, and the external reference voltage for analog output. The BNC-2111 also includes a single two-position switch that you can use to select between floating source and ground-referenced analog input signals.