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mentioned
correct this
391
B/392D
anywhere
one second too short
to
almost
twice
long.
Pulses
are not lost during
so totalized values are correct
but pulse
information such as
wind speed
twice the correct
value. The
can
be
discard
from excessive intervals option
the previous paragraph does not
in 21Xs
with PROMs
earlier.
The options pf discarding counts
from long
intervals, pulpe input
type, outputting frequency,
and using a $ixteen bit counter are selected by
the code entbred for the
fourth parameter
(Table 9-2).
NOTE: f,ll
pulse
count instructions
must
be
ikept
in
the same table.
lf
the
pulse cofrnt instruction
is
contained
within a bubroutine. that subroutine
must
beicalled from Table
2.
Codes
Configuration
High
frequency pulse
Low
levelAC
Switch closure
High
frequency pulse, sixteen bit
counter
Low
levelAC,
sixteen bit
counter
Long interval data discarded,
where X
is
configuration code
Long interval data discarded,
frequency (Hz) output
PARAM.
DATA
NUMBER
irYPE
DESCRIPTION
Repetitions
Channel number for first
measurement
Configuration
code (from
above table)
Input location for
first
measurement
Multiplier
Otfset
SECTION
9.
INPUT/OUTPUT INSTRUCTIONS
***
4
EXCITE,
DELAY, AND MEASURE ***
FUNCTION
This instruction is used to apply an excitation
voltage, delay a specified
time, and then make
a
single-ended
voltage measurement. A
1
before
the excitation channel number (1X) causes the
channelto
be incremented
with each repetition.
PARAM.
DATA
NUMBER
TYPE
DESCRIPTION
2
Repetitions
2
Range code
2
lnput
channel number for
first measurement
2
Excitation channel
number
05:
4
Delay in hundredths of
a
second
06:
4
Excitation voltage
(millivolts)
4
Input location number
for
first measurement
FP
Multiplier
FP
Offset
Input locations
altered:
1
per measurement
***
5
AC HALF BRIDGE
'**
FUNCTION
This instruction is used to apply an excitation
voltage
to a half bridge (Figure 13.5-1), make
a
single-ended
voltage measurement of the bridge
output, reverse the excitation voltage, then
repeat
the measurement. The result of
lnstruction
5
is
the ratio of the measurement to
the excitation
voltage. A
1
before the excitation
channel number (1X) causes the channel to
be
incremented with
each repetition.
The excitation
"on
time"
for each polarity
is
exactly the same
to insure that ionic sensors do
not polarize
with repetitive measurements. The
range should be selected
to be
a
fast
measurement
(range 11-15), limiting the
excitation
on
time
to 800 microseconds at each
polarity.
A
slow integration time should not
be
used
with ionic sensors because of polarization
error.
01:
o2:
03:
o4:
07:
08:
09:
Code
0
1
2
3
4
1X
2X
01:
Q2:
03:
04:
05:
06:
2
2
2
4
FP
FP
lnput locations altered:
1
per measurement
9-3
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