TM 5-6350-275-24&P
Figure 1-24. ICIDS Line Concentrator-General Block Diagram
d. Intelligent Audio Multiplexer. Figure 1-25, the ICIDS Intelligent Audio Multiplexer General Block Diagram, shows
more detail of the Audio Multiplex unit. This unit is more frequently used than the RS485 or Fiber Optic interfaces. Each
multiplex unit uses a 647180 micro-processor and through one of its UART ports polls the 8 lines associated with this
particular unit. Because of the built in intelligence, this unit selects the desired line among the 8 lines to listen for an
answer to the broadcast poll, thus eliminating reception from all lines in the group except the desired line. This method is
subject to far less noise because it concentrates on just one line of the 8. Thirty-two of these multiplex units are polled
for their data by the Data Communications Expander on the CPU. The DCX will poll the multiplex unit at 9600 baud,
while the multiplex unit has a selectable baud rate of up to 19.2 baud. It polls the RADC at 1200 baud. This will enhance
the performance and timing over the previous system. The DES module option and the link field indicate how the DES
module can be added to a group of 8 multiplexed lines. In addition to the standard data collection from the remote
locations, the communication support subsystem through these same multiplex units will also pass all access control card
information and access data as required. CCTV command messages will also pass through the same system.
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