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Model
562A
The following notes refer to tables 3 -1 and 3 -2:
1 and 0 definitions
1) 1 indicates "1" level binary input.
2) 0 indicates "0" level binary input.
Section III
"1" and "0" levels (BCD input)
1) In a +1224 code, the" 1" level is positive with respect to the "0" level.
2) In a -1224 code, the" 1" level is negative with respect to the "0" level.
The
+
or - prefix is deterrnined by the polarity of the" 1" level with respect
to the "0" level.
3-9. REFERENCE VOLTAGES.
Input to the binaries is through gates which are controlled by two dc -biasing
signals which control the passage of transfer pulses.
One of the biasing signals
is the BCD data input and the other is a reference voltage.
The transfer pulses
are internally-generated within the recorder.
The inputs to the binaries are
capacitively-coupled and may be floating with respect to chassis ground.
The
reference voltage is thus required to establish a point to which the BCD sig'nal
is referred.
Two reference voltages are required in the data storage system
and should generally be the steady dc values of the 0 and 1 states of the BCD
input signal.
This relationship of reference to BCD signal is shown in figure
3-1 for a negative-going signal equal to the 1 level.
"0"
"1"
SIGNAL
TO BE WITHIN
±
150V TO GND.
POS.
OR "0" REFERENCE
NEG. OR"
1"
REFERENCE
It
I" EQUALS
NEGATIVE-GOING
RO
Figure 3
-1.
Reference Levels.
01081-1
3-5
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