Many manufacturers sell signal generation platforms, which can be populated with multiple modules providing the above capabilities (and supporting different formats).
These devices are generally intended for off-line use (test patterns are seldom broadcast, unless a station is not operating properly or is off the air at the time), as they output complete television signals.
Examples of signals output by such a device include: Some generators achieved a relative popularity, due to channels broadcasting test cards for long periods where no programming was scheduled.
Unlike test signal generators; a VITS inserter is used to insert the test signal into live programming, so that inline measurements of a transmission chain can be made while the chain is operational.
(As the vertical interval is typically not visible on end-user televisions, this can be done without producing any artifacts noticeable to viewers).