The DIP switch configuration is covered in the ECO422D user manual and in the quick reference card that ships with the instrument. There are 11 banks of switches labeled S1 through S11 which correspond to the 11 pairs of signal inputs. Each of these banks of switches needs to be configured to indicate to the ECO422D what type of signal to expect on the corresponding input BNC's. The switches are arranged as shown below: The DIP switch settings for each kind of signal are: All open = Disabled (signal not checked) 1 = NTSC Black Burst 2 = PAL Black Burst 3 = NTSC Serial Digital Video (143 Mbps) 4 = Serial Digital Video (270 Mbps) OR Analog tri-level sync 5 = Serial Digital Audio (AES) 6 = User Defined 7 = User Defined 8 = On channels 1-6: Serial Digital Video (1.485 Gb/s) 8 = On channels 7-11: Attenuate input for purposes of checking, output remains identical to input (used for checking large amplitude signals)