Datavideo CB-42 Tally Cable for SE-500HD and SE-650

The CB-42 is the tally cable Datavideo specifies between the SE-500HD and SE-650 switchers and the RMC-180 controller, carrying the on-air indication from the switcher out to the tally system.

It is the correct factory part for that link rather than a generic substitute, which matters because the pinout is specific to those units. Datavideo also lists it under the internal number G07692150202.