Output dependency in delay mode.

This requirement comes from the main client of the card (CERN TE-ABT).

The reasons are:

- The module currently used in the installation has a shared output counter (so it is not possible to have independent outputs), and the Fine Delay is intended as its replacement.
- If all channels will be made independent, it could be that some outputs could send out less pulses than others (when the input T is lower than the set delay time for that channel).

Note that this limitation does not apply when the card is configured in Pulse Generator mode.