AIR FORCE
T.O. 10M1-7-9-1-1
ARMY
TM 11-5895-1021-14/1
MARINE CORPS
TM 08045-15/1
SECTION IV
THEORY OF OPERATION
4-1. GENERAL.
4-2
Theory of operation for the II Segment is limited to intershelter communication and segment power distribution. More
detailed theory can be found in the shelter manuals listed in table 1-1. Intershelter communication is divided into two
communication channels high speed digital data and voice communications. The following paragraphs provide theory for
the two communication channels and describe segment power distribution.
4-3. HIGH SPEED DATA COMMUNICATIONS.
4-4. The II Segment shelters are interconnected in an automatic data processing (ADP) network for digital
communications. Through successive multiplexer (XIO) links, it IS possible for one shelter to establish a data path to any
other shelter. To demonstrate this, consider a three-shelter system as shown in figure 4-1. The computer in shelter 1 can
command a link to channel 3, enabling data communications with the XIO in shelter 2. The computer can then command
a link through the shelter 2 XIO to channel 6, enabling data communications with the shelter 3 XIO. This process can be
repeated until the desired shelter in the segment is reached. For practical reasons, communication has been limited. An
I-Shelter needs to transfer data only to its A-Shelter and an A-Shelter needs to transfer data only to its I-Shelters, IA-
Shelters, and other A-Shelters of its operational segment.
4-5. The high-speed digital data transfer is on a computer-to-disk basis. The location of the transmitting and receiving
equipments does not affect the operation so long as links can be established between them. All XIOs are assigned
Identification codes through use of a switch inside the XIO Commands are acted upon by the XIO only if the Identification
code corresponds to the XIO identification code. If the identification code does not correspond, the command is passed
through the active link to the output
channel.
4-6. Refer to figure 4-1 for the following discussion. For purposes of this discussion, assume an A-Shelter (AS100) sends
a message to CPU 1 in I-Shelter (IS210). Then assume that the XIOs are identified 001 (AS100), 010 (AS200), and 101
(IS210) The AS100 CPU outputs a link-to-channel-3 command addressed to XIO 001. XIO 001 links the CPU channel to
channel 3. When the link is acknowledged, the CPU outputs a link-to-channel-6 command addressed to XIO 010. XIO
010 links its channel 3 to channel 6 The CPU then outputs a link-to-disk command addressed to XIO 101. The AS100
CPU then writes the message on the CPU 1 area of the disk in IS210 CPU 1 in IS210 recognizes the message the next
time it polls the disk.
4-7. VOICE COMMUNICATIONS.
4-8. An II Segment intercom system is provided to enable voice communications among various positions of the segment.
Two intercom sets are contained within each I- and A-Shelter and one set Is in each IA-Shelter. Each A-Shelter intercom
set can establish voice links with from 1 to 16 other intercom sets at one time. Each I- or IA-Shelter intercom set can
establish voice links with from 1 to 15 other intercom sets at one time.
4-1
