Advertisement
Page 4-5
THEORY OF OPERATION, CONTINUED
TRANSMITTER UNIT CONTROL THEORY, Continued
together when that channel is selected and a raise or lower command
18
given.
These pins are completely isolated for each channel by way of three contacts in
each channel relay.
The raise/lower relays are fused in the line to terminal
SiX.
Channel zero 1S connected internally to the raise/lower relays
but is
otherwise isolated 1n the same manner as each of the other channels.
TRANSMITTER
UNIT
TELEMETRY THEORY
For each channel the data is applied to ends of a lOOK pot adjusted from
the front of the RY-15.
The tap and one end of each pot connects with two poles
of the appropriate channel relay.
Upon channel selection, the calibrated sample
of data is connected to the DPM in the transmitter unit.
There it is converted
into digital display and BCD outputs.
These are fed into the UART's in the trans-
mitter unit through buffers and optical isolators.
Grounding status inputs cause appropriate indicators on the Transmitter Unit
to light and that condition is entered into the UART.
Grounding the alarm input will cause the indicator on the front panel of the
Transmitter Unit to light, and
if
the channel zero
~s
selected, wilL turn the te-
lemetry signal on.
Whenever the telemetry is on, 1/2 of a 556
drives the commOn
terminal on the rear of the RMC l5T with 11.5 Volts.
Grounding of Disable 1 will
inhibit the generation of a telemetry signal.
The polarity, status states, digit
1000, and the hundrQd's place disit
are transmitted in the first half of the
doubleword
telemetry signal.
The basic method of developing clock and word rates
are like those in transmitting the control word from the Studio Unit except that
the telemetry double word is sent every
480 clock cycles and that if subaudible
telemetry is used the clock frequency is fixed.
After transmission of the first
half of the doubleword, the first UART triggers transmission from the second UART
which sends the one's place and ten's place digits.
The high logic interval of
140 cycles between doublewords is used in the reset generation circuit at the
Advertisement
