NOTE: EMIR subbands, IF cables, and Backends

The output signals from EMIR are transmitted to the spectrometers and
NBC through 8 IF cables. Each IF cable carries one subband of bandwidth
4 GHz. This subbands are LO, LI, UI, or UO.

NBC, 4MHz, WILMA, and VESPA can only(!) be connected to IF cables 1 to 4.
FTS parts 1 to 4 can also be connected to IF cables 1 to 4.  

The command options RECEIVER /HORIZONTAL and RECEIVER /VERTICAL allow
to select up to 4 EMIR subbands that will be transmitted through IF
cables 1 to 4 (compare HELP RECEIVER /HORIZONTAL and the EMIR user
documentation). This selection can include Outer subbands.

In addition, the IF cables 5 to 8 carry the 4 Outer subbands
corresponding to the subbands selected for IF cables 1 to 4. E.g., if
we select for IF 1 to 4:
E230 ver UO    E090 ver UI    E230 hor UI   E090 hor UI
then the IF cables 5 to 8 will transmit: 
E230 ver UO    E090 ver UO    E230 hor UO   E090 hor UO.

Only FTS parts 5 to 8 can be connected to IF cables 5 to 8.

BACKEND NBC|WILMA|FTS /DEFAULT will automatically set the maximum
number of backend parts for all available subbands.

BACKEND BBC is completely independant of the sub band selections for
the IF cables.
