TM
11-6625-3041-30/TO
33A1-8-908-12
1-19. RECEIVE 2 (A6) BIT ERROR RATE (CONT)
If the output from the Red Error Sel goes high (indicating an
error count of 10 or 100 has been reached) the true errors
signal clocks in the D input, which sets the Q output of the
Red Status high. This high output lights the red front panel
NO GO indicator through the Red Lamp Control.
If the output from the Red Bit Sel goes high before the output
Red Error Sel goes high (indicating the error count of 10 or
100 was not reached before the total number of 10,000 or 1OO,00O
bits was counted), the output from the Red Bit Sel clears the
Red Status (sets its 0 output low). This prevents the NO GO
indicator from lighting.
For example, if the
DATA RATE control is
set to 512 (128-4608
family) the zero
level 04 Decode II
output sets the Red
Error Sel for the 100
output and the Red
Bit Sel for the 105
output (100 errors
per 100,000 bits).
If 100 errors are counted before 100,000 bits have been counted,
the red NO GO indicator lights.
Red
The output from the Red Status is applied to the Red Lamp Con-
trol, which includes a driver to light the NO GO indicator. It
Lamp Control
also includes a latch so that the results from one BER measure-
ment can be indicated while another measurement is in progress.
A second output is applied to both the Yellow and Green Lamp
Controls. A NO GO indicator inhibits both the MARGINAL and
GO indicators.
Except for the error count of 2 and 10 (instead of 10 or 100)
Yellow
and bit count of 200,000 and 1,000,000 (instead of 10,000 and
100,000), the Yellow circuits operate in the same manner as
the Red. The output lights the yellow front panel MARGINAL
indicator.
Green
A second output from the Yellow Lamp Control is applied to the
input of the Green Lamp Control. If the Yellow Lamp Control
Lamp Control
is active (has lit the yellow MARGINAL indicator) the output
to the Green Lamp Control is high, which inhibits the green
front panel GO indicator.
If the Yellow Lamp Control is not active, the output to the
Green Lamp Control is low, which lights the green front panel
GO indicator.
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