Racal Instruments 9901 Maintenance Manual page 11

DATA
FORMAT
PRINCIPLES
DATA OUTPUT
FORMAT
A4.
In
standard format the
b.c.d.
output data
Is
available
at the
28-way
edge
connector
in
a
bit parallel
byte
serial form.
The
data
is
sequenced by a
10
kHz
synchronising
signal.
The
data presentation
is
delayed 0.5
ps
from the negative
edge
of the S)^nchronising signal.
An
additional synchronising pulse
(Ro)
determines
the
first
state
(10
digit).
Accessories are available
to give data output
in
parallel
format
(for
printers etc.) or lEC/ASCII
bus compatible
format. (Options)
The
ten
data output
states are
as follows: the timing
Is
shown below.
States
Facility
1
fo 8
Digit (display information).
9
Overflow
for
10^, 10^,
10^ and 10^
digits
on
pins
D,E, 4 and 5
respectively.
10
Decimal
point posjTion
in
kHz
units, plus
overflow
information
for
10^
digit, via pin 5.
I
I
1
100
VS
I
I
I
10
KHz
SYNC.
(PIN FI
Ro (PIN
12)
OUTPUT STATES
DATA OUTPUTS
0-5
MS
1
2
I
10 ^
1
10
^
5
I
6
I
7
I
8 9
to
7
10
1
DIGIT
DATA
Data Sequence Diagram
OVER OVERFLOW
FLOW
AND
dp.
Fig A.1
9901
Vol.2
Tech. Spec.
(9)