nonresident training course - Historic Naval Ships Association

Figure 4-5.—Central data buffer (CDB) functional block diagram.
Scanner Control and Clock Generation
The scanner control and clock generation
function provides the controls to connect the CIU to
a DMU. A scanner enable signal is generated and
sent to a CIU. If the CIU needs to be connected to
a DMU, it generates a DMU request. The scanner
and clock generation function will connect the
requested DMU to the requesting CIU for data
transfer. The scanner and clock generation function
also generates all system clocks used by the CDB.
CDB Front Panel
The CDB front panel is shown in figure 4-6.
The front panel provides the power control and
monitoring. The four display channel switches are
used to select the display source data. In the AUTO
position, any computer can automatically interface
with the CDB. If the switch is set to select a
particular computer, that computer will be the only
data source. The CDB can be tied to six computers;
therefore, the computer 7 and the computer 8
positions are not used.
Display channels 1 and 2 can be tied to the same
data source when required by placing the DATA
SOURCE SELECT switch in the BACKUP position.
If you want display channel 1 to use the same data
source as display channel 2, place the display
channel 1 DATA SOURCE SELECT SWITCH in
the BACKUP position. For display channel 2 to use
display channel 1’s data source, place the DISPLAY
Figure 4-6.—Central data buffer (CDB) front panel.
4-5