Telecast Adder 162 User Manual page 32

The Adder 162/322 circuit block diagram shown in Figure 31 is a representative system with
one 8-channel module in each unit. The Adder 162/322 operating as a transmitter accepts up to
32/64 audio inputs and up to four digital inputs. Time division multiplexes them onto a single
optical fiber or coaxial cable.
Figure 31: Electronic Block Diagram
Demultiplexed signals are fed to corresponding output connectors on an output module. 2
Coaxial cables may be optionally used instead of fiber optic cable. However, redundant coaxial
cable operation is not available. All signals on the fiber or coaxial cable are digital, and therefore
relatively insensitive to transmission level variations.
The digital input buffer circuit accepts both data signals (RS-232, RS-422) and contact closures
and delivers this information to the multiplexer. The closure handling portion of the circuit
accepts information only from D-subminiature data connectors 1 and 2. Refer to Figure 32.
The circuit accepts a contact closure indicated by the switching of pin 8 to ground level pin 3.
This can also be accomplished by a TTL connection closure with pin 3 as the ground reference.
The digital output buffer circuit accepts the demultiplexed data and contact closure signals and
provides them at appropriate levels to the D-subminiature data connectors. Refer to Figure 33.
The output closure output is via an SPST-NO 1 FORM A relay; this closure is isolated and not
ground referenced.
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