Fluke 8505A - Page 63

With any trigger mode,
no command string is examined until the existing reading or recalled value is returned. Any
reading or recall
value commanded (but not yet returned) can be
discarded
by
sending the halt
(%)
command.
If
a
continuous
trigger mode
(T or
Tt)
is in effect
when
(%)
Is sent,
the multimeter configuration is changed to single
trigger
mode
(TO or T2),
and any buffered
commands
(with
a
terminating character) are executed.
AVERAGING
COMMAND CHARACTERS
With the 8505A (all
functions) and the 8506A (dc volts, ohms, dc amps only), the‘‘0"character is used to command a
preset sample
and filter combination for each function and range to optimize
accuracy and stability. Averaging also
provides
an extra digit
of resolution in several ranges
(as
defined
under
RANGE COMMAND CHARACTERS). The
following commands
are available:
1
. O
:
Averaging mode enabled.
2.
OO
:
Average mode disabled.
Enabling of Average mode
in the situations defined above sets the multimeter to sample
S10
and filter F, With
Average mode
enabled, samples SI 1-SI 7 or filter F2 can also be selected. Disabling of Average mode changes the
sample and
filter again and occurs under any of the following circumstances:
1.
Command OO
is
sent,
Averaging
mode is disabled. The sample is set to S7
and
the
filter is set to FO.
2. The
function is changed. The sample is set to
S7
and the filter is set to FO. if an ac volts function is initially
selected with the 8506A, only filter FO is set. If
a
change is made between 8506A ac volts functions (VA,
VA1, VA2, C, Cl, C2), Averaging (extended resolution) is retained.
3. A sample
or filter not allowed in Average
mode
is commanded. If
S0-S9 is
commanded, Average mode is
disabled, the new
sample
setting is accepted and the filter is set to FO. If
a
filter
other than
F or
F2 is
selected,
Average mode is disabled, the new filter is
accepted
and
the
sample is set to
S7.
With the 8506A
set for any of the ac volts functions,
Average
mode
is
not available. However,
theOjor OO command
can still be used to
enable or disable extended resolution
(as
defined under RANGE COMMAND CHARACTERS).
In
this situation, only
the sample and filter restrictions
defined by
the 8506A
ac volts
functions are applicable. No
sample change
can be made. Only filter FOor F
(for
input signals less than 40 Hz)
can be
selected. If a sample change
is attempted
or an unallowed filter is commanded,
a
momentary error is
set and extended
resolution is retained.
Extended
resolution in 8506A ac volts functions is disabled if theOO command is sent, if
a
change is made between ac
volts
functions, extended
resolution is
retained with the existing filter mode. If
dc
volts, ohms, or
dc
amps is selected,
extended
resolution (Average mode) is disabled, the filter is not
changed,
and the sample is set to S7.
Whenever
the
“O”
character is used (8505A or 8506A
-
any function), the multimeter responds with the following output
format:
BINARY OUTPUT FORMAT
16-Bit
Format (B1):
BYTE 1
BYTE
2
8-Bit Format (B):
BYTE 1
BYTE 2
Example:
BYTE 3 BYTE 4 BYTE 5 BYTE 6
BYTE
3 BYTE 4
BYTE
5
1
BYTE
6
0000
001 1 1000 0000 0000 0000
Implied
Binary Point
Sign Bit
=
3.5 X 10
EXP 1
0000 0000 0000 0000
Exponent Sign Bit
0000
0001
J
J
V