Philips PM2517X - 3.4.7. OO 0063 Programmable Current Source; 3.4.7.1. General

50
Description
Data input
Auto
zero
lnverse of
auto
zero
Polarity
Data
Hold
Overrange
BCD information
GRouND
+
14
15
to
11
AZ
DATA
POL
OVF
Incoming
data with
a
duty-cycle
depending
on the
input
voltage
of
the
ADC.
During
the
second
measuring
period
the DATA
signal
is
anverted,
Auto
zero
outputs
are used
for commutating
the
input
voltage of
the
V-l
convertor
for automatic
zero
compensation.
The
state
of signal
PO L is determined
by the
input
voltage of
the
Pl\4
2517,
which
is measured
by
the
ADC.
LOGtC0=_potarity
LOGIC I
=+
polarity
Logic 0 normal
measuring.
Logic
1
the
present
value
of the
last completed
measuring
cycle
will
be held.
lf
DH becomes 1 the
measuring
cycle
will be
ended, there
is no
transfer of
measured
data.
The
control logic wilt be
waiting
until
DH becomes
0, and a
new
measuring cycle
will be
started.
When a measuring
result
is ) 9999
in the highest
permisseable
range
(in
manual or
automatic
ranging
mode)
then signal OV
R
will
become logic l. Signal
OVR
is
supplied
to the display.
In case of overload
only
digit
'l02
and
also the corresponding
decimal
point
is ignited.
BCD coded
result.
Bit
parallel-word
serial.
Together
with the signals
DS1 and DS2
(digit
select) the
correct
digits in the correct
order can be made
visible.
Supply Zero.
0 V ü
20
21
23
24
A2
A1
AO
GND