Figure 1-22.-COMM interface No. 1.
over voice radio. Switches on the front of the box
provide control over data conversion,
TSEC/KW-7 Security Unit
This unit provides encryption and decryption of the
baudot code. It is used
whenever the teletype
Unit Remote Control
This unit is located next to the TTY keyboard and
enables the operator to control the TSEC/KW-7 without
having to leave his/her seat.
Teleprinter Secure Interface
Mounted under the TTY keyboard, this unit
provides remote selection of secure or clear TTY
operation. By placing the red guarded TTY/TPR switch
to the BYPASS position, the operator closes a relay to
bypass the TSEC/KW-7.
Communications Interface No. 1
This unit (fig. 1-22) connects the TTY system with
the central computer. It converts the baudot code into
30-bit, parallel, binary computer language. The switches
and controls on the front of the interface are inoperative
in the OPERATE mode.
TELETYPE SYSTEM OPERATION
Figure 1-23 shows the teletype system block
Off-line operation of the TTY system requires the
operator to select an appropriate frequency on the HF-1,
HF-2, or UHF-2 control panel and to select TTY mode
on the communications selector panel. The selected
radio is automatically mode forced into a data
transmission mode. The operator selects words per
minute (WPM) speed (normally 100) and TTY on the
HSP, and DIR SEND on the TTY keyboard. Phasing the
TSEC/KW-7 sends a synchronization signal that is
received by all other units on the frequency. Once all
units are synchronized, they are ready to accept data.
When a key is depressed on the TTY keyboard, the
corresponding baudot code is generated. This is sent to
Figure 1-23.-Teletype system block diagram.