MIL-STD-187-721 Interoperability And Performance Standard For Advanced Adaptive Hf RadioThe purpose of this document is to describe the technical parameters for adaptive high frequency HF radio that are more advanced than those described in MIL-STD-188-141. The advanced technology contained in this standard will guide the planning of military adaptive HF radio network technology into the 21st century. To fully understand and utilize this document, it is necessary to refer to portions of MIL-STD-188-141.

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MIL-STD-187-721D

is carrying the command.  The other bits may be employed to control any other analog ports at a station.

NOTES:

1.  Multiple inputs and outputs may be simultaneously enabled by this command.  If the equipment at a station cannot fully implement a command, the equipment should approximate the requested effect as nearly as possible.

2.  This functionality may also be accomplished at the HFNC level.

FIGURE 16.  Analog port selection CMD format. TABLE XVII.  Analog port selection bits.

5.6.4.4  Data port selection.

a.  The data port selection command is used to specify the destination for the immediately following DTM or DBM.  By default, any DTM or DBM message that arrives without an immediately preceding data port selection CMD is assumed to carry a message for the station operator, and is routed to an appropriate data port (e.g., an operator display or a printer).

The station operator data port (the default) may also be explicitly specified by preceding a message with a data port selection CMD with a port number of 0.  A message destined for an attached network controller shall be preceded by a data port selection CMD with a port number of 1.  A message intended for over-the-air fill shall be preceded by a data port selection CMD with a port number of 2 (see figure 17).  Other port numbers from 3 through

15 have station-specific meanings.

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